invited lecture (il1-il12) · 2017. 7. 19. · many diols and dicarboxylic acids can be produced...
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Invited Lecture
(IL1-IL12)
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IL1 Synthetic biology for intracellular and secretory production of polymerized ester-products in Escherichia coli
Seiichi Taguchi,*1,2,3 Camila Utsunomia,2 and Ken’ichiro
Matsumoto2,3 1Department of Chemistry for Life Sciences and Agriculture, Tokyo
University of Agriculture, 2Graduate School of Engineering,
Hokkaido University and 3JST-CREST
E-mail address: st206172@nodai.ac.jp
In our previous study, the first incorporation of lactate (D-LA) into the P(3HB) backbone in
the Escherichia coli-based microbial factory carrying a newly developed D-LA-polymerizing enzyme
LPE was reported [1, 2]. LPE was one of the artificially evolved PHA synthases through our long-term
enzyme engineering study [3, 4]. In the second generation, LPE has led us to further expand the range
of structural diversity of PHA members other than D-LA-based polymers. As second targets, glycolic
acid [5] and D-2-hydroxybutyrate [6] can also be polymerized by LPE to generate new copolymers [7,
8]. Like these, I expected to synthesize the chiral copolymers with various monomer compositions,
owing to the extremely high enantio-selectivity and broad substrate specificity of LPE. In this
symposium, I will talk about the overview of biosynthesis and properties of LPE-catalyzed polymers.
For long time I have been thinking about the possibility of “SECRETION” of polymerized
ester-products by microbial platform. This should be a promising issue to overcome the cell volume
limitation in the large amount of production of natural or chemical polymers (oligomers). Fortunately,
we have met to the “SECRETION” of low-molecular-weight D-LA-based polymers [or D-LA-based
oligomers (D-LAOs)]. As a second topic, I will talk about the first observation of microbial secretion
of D-LAOs and its advanced microbial secretion platform through the chain transfer reaction and
modified cultivation conditions [9].
References
1. S. Taguchi et al., Proc. Natl. Acad. Sci. U.S.A., 105, 17323-17327 (2008)
2. K. Tajima et al., Macromolecules, 42 (6), 1985-1989 (2009)
3. S. Taguchi and Y. Doi., Macromol. Biosci. (Review), 4 (3), 145-156 (2004)
4. K. Matsumoto, T. Shiba, Y. Hiraide, S. Taguchi, ACS Biomat. Sci. Eng., DOI:
10.1021/acsbiomaterials.6b00194
5. K. Matsumoto et al., Biomacromolecules, 14(6), 1913-1918 (2013)
6. K. Matsumoto and S. Taguchi, Curr. Opin. Biotechnol. (Review), 24(6), 1054-1060 (201
3)
7. K. Matsumoto and S. Taguchi, Appl. Microbiol. Biotechnol. (Mini-review), 97(18), 8011-
8021 (2013)
8. C. Utsunomia, K. Matsumoto, and S. Taguchi, ACS Sustain. Chem. Eng., DOI:
10.1021/acssuschemeng.6b02679 (2017).
9. C. Utsunomia, K. Matsumoto, S. Date, C. Hori, and S. Taguchi, J. Biosci. Bioeng., DOI:
10.1016/j.jbiosc.2017.03.002 (2017).
http://pubs.acs.org/author/Tajima%2C+Kenji
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IL2 Finding new superior PHA synthases for the biosynthesis of novel microbial biopolyesters
Kumar Sudesh
School of Biological Sciences, Universiti Sains Malaysia, 11800
Penang MALAYSIA
ksudesh@usm.my
Polyhydroxyalkanoates (PHAs) are biopolyesters synthesized by a wide variety of bacteria as a
storage polymer that is not unlike glycogen in animals and starch in plants. Upon extraction and
purification from the bacterial cells, PHAs show thermoplastic properties similar to polypropylene and
low-density polyethylene. Unlike petrochemical plastics, PHAs are 100% biodegradable in various
natural environments. The renewable nature of PHAs makes them attractive as potential substitutes for
some non-biodegradable single use commodity plastics. In addition, PHAs are also biocompatible and
have much potential as a biomaterial for medical applications. The key enzyme involved in the
biosynthesis of PHA is PHA synthase, which determines the type and molecular weights of PHAs
synthesized. The PHA synthase of Chromobacterium sp. USM2 has the highest polymerizing activity
reported to date. It also has broad substrate specificity enabling it to polymerize 3-hydroxyalkanoate
monomers comprised of 4-7 carbon atoms. However, it lacks the ability to polymerize 4-
hydroxybutyrate. The PHA synthase of Aquitalea sp. USM4 has an amino acid sequence identity of
78% to that of Chromobacterium sp. USM2 and with the ability to polymerize 4-hydroxybutyrate but
not 3-hydroxyhexanoate. Another PHA synthase was identified from mangrove metagenome with the
ability to polymerize 3-, 4- and 5-hydroxyalkanoates ranging from 4-6 carbon atoms. These newly
discovered PHA synthases show great potential for the biosynthesis of new types of PHAs for both
environmental and medical applications. The recent successful determination of the 3D structure of
Chromobacterium sp. USM2 PHA synthase catalytic domain opens new frontiers for the
understanding of its polymerizing mechanism and the development of superior PHA synthases through
protein engineering.
References
1. Bhubalan, K., J.-A. Chuah, F. Shozui, C. J. Brigham, S. Taguchi, A. J. Sinskey, C. Rha and K.
Sudesh. (2011) Characterization of the highly active polyhydroxyalkanoate synthase of
Chromobacterium sp. strain USM2. Appl. Environ. Microbiol. 77(9):2926-2933.
2. Ng, L.-M., K. Sudesh. (2016) Identification of a new polyhydroxyalkanoate (PHA) producer
Aquitalea sp. USM4 (JCM 19919) and characterization of its PHA synthase. J. Biosci. Bioeng. 122(5):
550-557.
3. Foong, C. P., M. Lakshmanan, H. Abe, T. D. Taylor, K. Sudesh (2017) A novel wide substrate
specificity polyhydroxyalkanoate (PHA) synthase from uncultured mangrove bacterium. Poster
session presented at the 6th International Conference on Bio-based Polymers (ICBP2017), Taoyuan,
Taiwan.
4. Chek, M. F., S.-Y. Kim, T. Mori, H. Arsad, M. R. Samian, K. Sudesh and T. Hakoshima. (2017)
Structure of polyhydroxyalkanoate (PHA) synthase PhaC from Chromobacterium sp. USM2,
producing biodegradable plastics. Sci. Rep. (accepted).
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IL3 Evaluation of Environmental Degradability of Poly(butylene n-alkylenedionate) and Control of Environmental Biodegradation under Reductive Condition Yuya Tachibana, Takuro Baba, Shota Suda, Kohei Kageyama, and
Ken-ichi Kasuya*
Division of Molecular Science, Faculty of Science and Technology,
Gunma University, 1-5-1 Tenjin, Kiryu, Gunma, 376-8515, Japan
E-mail: kkasuya@gunma-u.ac.jp
Many diols and dicarboxylic acids can be produced from biomass resources. Recently poly(n-
alkylene n-alkylenedionate) (PAAD) comprising long-chain-aliphatic diol and dicarboxylic acid has
attracted much attention as high-performance bio-based polyester. Additionally some PAADs are
believed to be biodegraded easily. However, comparative studies of biodegradability have been limited
to only a few types of typical PAADs. Therefore, we prepared nine poly(butylene n-alkylenedioate)
(PBAD)s having 2–14 methylene units in the dicarboxylic acid and evaluated the biodegradability of
these PBADs by biochemical oxygen demand (BOD)-biodegradation testing1. The frequencies of the
degrading microorganisms in 19 sites varied with the structure of PBADs. Additionally, BOD-
biodegradation rates of PBADs (n = 2 and 10) were much lower than those other PBADs. PBAD (n =
11-14) did not show BOD-biodegradability. Thus, the environmental degradability of PBADs could
be related to the frequencies of species that produced the degrading enzymes.
Figure 1. Biodegradation of poly(n-alkylene n-alkylenedionate)
The biodegradation testing of PBADs indicates that PBAD comprising long-chain dicarboxylic acid
is not biodegradable polymer while it has good physical properties. A trigger system that uses external
stimuli to change the chemical properties of a polymer or directly degrade the polymer to low
molecular weight compounds is suitable for controlling the biodegradability of such polyester. We
adopted the reductive cleavage of disulfide bonds as a trigger to control the biodegradability of
polyesters2. We synthesized polyesters with disulfide bonds and demonstrated that the environmental
biodegradability of these polyesters could be triggered by cleavage of the disulfide bonds in a reductive
environment.
Figure 2. Reductive cleavage and biodegradation of polyester comprising disulfide bonding
References 1. T. Baba, Y. Tachibana, S. Suda, K. Kasuya, Polym. Degrad. Stab, 138, 18-26 (2017). 2. Y. Tachibana, T. Baba, K. Kasuya, Polym. Degrad. Stab, 137, 67-74 (2017).
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IL4 Polyhydroxyalkanoate production by marine purple photosynthetic bacteria
Mieko Higuchi-Takeuchi, Kumiko Morisaki and Keiji Numata*
RIKEN Center for Sustainable Resource Science, Enzyme
Research Team
Polyhydroxyalkanoate (PHA) is a family of biopolyesters that a variety of microorganisms accumulate
as carbon and energy storage under the starvation condition in the presence of excess carbon. Therefore,
PHA production requires a cost-consuming carbon source. Use of photosynthetic organisms to produce
materials is one of the potential methods to reduce costs and can contribute sustainable system because
they can utilize sun energy and carbon dioxide in the air for their growth. In this study, we focused on
marine photosynthetic purple bacteria as host microorganisms for PHA production.
Three purple sulfur bacteria and nine purple non-sulfur bacteria that showed better growth
were selected. Twelve purple photosynthetic bacteria were cultured in nitrogen-limited liquid media.
The synthesized PHAs were characterized in chemical compositions and molecular weight (Table 1).
In the case of purple sulfur bacteria, PHA production was induced by nitrogen limited conditions and
they synthesized 3HB homopolymer. Purple non-sulfur bacteria produced PHAs under nutrient rich
conditions and synthesized copolyesters of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV).
Gel permeation chromatography analysis revealed that some strains synthesized high-molecular-
weight PHAs. Quantitative RT-PCR analysis revealed that mRNA levels of PHA biosynthesis genes
(phaC and phaZ) were low, resulting in production of high-molecular-weight PHAs.
To diversify marine PHA-producing strains, we established a method for the isolation of
PHA-producing purple non-sulfur bacteria from natural seawater. Natural seawaters were cultured in
nutrient-rich medium and pigmented colonies were picked up. One isolate accumulated 24.4 wt% PHA,
and 16S rRNA gene sequence analysis revealed that this strain showed high similarity to marine purple
non-sulfur photosynthetic bacteria.
PHA synthase from Rhodovulum sulfidophilum (PhaCRs) was produced by a cell free protein
expression system and characterized its activity. The polymerization activity of PhaCRs increased
linearly with increasing concentrations of (R)-3-hydroxybutyryl-CoA (3HB-CoA) and did not saturate,
suggesting that the PhaCRs was not saturated due to low affinity for the substrate. Size exclusion
chromatography and Native PAGE analysis revealed that PhaCRs existed predominantly as a dimer
even in the absence of 3HB-CoA. Dimerization of PhaC is considered to be the rate-limiting steps for
PHA polymerization. Linear relationship between the PhaCRs activity and concentrations of 3HB-CoA
might result from low affinity for the substrate as well as the absence of rate-limiting step due to the
existence of predominant active dimer. These properties are quite different from well-known PhaC.
Table 1. Number-averaged molecular weight of purified PHA and PHA compositions
Organism Sulfur type Number-average molecular
weight (gmol-1)
PDI PHA composition (%)
3HB 3HV
Thc. marina Sulfur 645 X 103 3.7 100 0
Mch. bheemlicum Sulfur 994 X 103 5.8 100 0
Rdv. imhoffii Non-sulfur 570 X 103 6.7 96.1 3.9
Rdv. tesquicola Non-sulfur 504 X 103 3.4 71.4 28.6
Rdv. visakhapatnamense Non-sulfur 713 X 103 3.4 98.2 1.8
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IL5 Biosynthesis and degradation of unusual microbial polyesters
Ken’ichiro Matsumoto,*,1 and Seiichi Taguchi1,2 1Applied Chemistry, Engineering, Hokkaido University,
mken@eng.hokudai.ac.jp, and 2Department of Chemistry for Life
Sciences and Agriculture, Tokyo University of Agriculture
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Microbial polyesters are biobased and biodegradable polymers that can be alternate petroleum-based
and non-biodegradable plastic. The class of polymers attracts research interest because of they can
potentially reduce the impact of plastic pollution on the environment. Our group has worked on the
synthesis of unusual polyesters using engineered enzymes and pathways. In particular, lactate-based
polymers and glycolate-based polymers are potent materials due to their flexible physical properties,
and their degradability.
Poly(D-lactate-co-3-D-hydroxybutyrate) [P(D-LA-co-D-3HB)], which is a hybrid random
copolymer of P(D-3HB) and PDLA, is efficiently produced from sugars in genetically modified
Escherichia coli [1]. P(3HB) is well-known biodegradable polymer digested by the action of
extracellular esterase called PhaZ, whereas little is known for degradation of PDLA. Our investigation
indicated that PDLA is NOT biodegraded in soil at least for 3 months. In contrast, P(67 mol% LA-co-
3HB) copolymer was found to be well-degradable, although 2/3 of monomer units are LA. The analysis
of degradation products revealed that the linkage between LA-LA was digested by PhaZ. Then, why
is PDLA not degraded? Eventually we found that the degradation of the polymer is not dependent on
monomer sequence, but is influenced by the "length" of substrate. But why? To answer this question,
we investigated molecular dynamics simulation of the substrates in aqueous conditions, and the
interaction between PhaZ. In fact, the results provided an insight into the mechanism of the degradation
phenomenon [2].
Poly(glycolate-co-3HB) was also efficiently produced in engineered E. coli. The glycolate-based
polymers exhibited non-enzymatic hydrolytic degradability. The thermal treatment of P(15 mol%
glycolate-co-3HB) emulsion resulted in the solubilization of the polymer into 3HB-based oligomer
with 6 mer in average length, suggesting that glycolate units in the polymer chain was digested more
rapidly than 3HB backbone [3]. Overall, these results demonstrated that the unusual microbial
polyesters exhibit unique degrading properties, and therefore, possess wider potential applications
compared to naturally synthesized microbial polyesters.
Reference
[1] D. Ishii et al. Polymer, in press.
[2] J.Sun et al., Appl Microbial Biotechnol, 99 (2015) 9555-63.
[2] K. Matsumoto et al., ACS Biomat. Sci. & Eng. In press.
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IL6 Renewable Vinyl Monomers and Their Precision Polymerization for Novel Functional Materials Kotaro Satoh*1,2
1 Department of Molecular and Macromolecular Chemistry,
Nagoya University, Nagoya 464-8603, Japan 2 JST-PRESTO
satoh@chembio.nagoya-u.ac.jp
Bio-based polymer material from renewable resources is now attracting much attention from the
viewpoint of environmentally benign and sustainable chemistry. Although this viewpoint is still
controversial in some aspects, the suitable and judicious applications of specific or complicated
structures originating from natural products is definitely beneficial for developing high performance
or functional bio-based polymeric materials. Meanwhile, a large number of precision polymerization
techniques for vinyl monomers are now available, which have been developed since starting the era of
petrochemical industry, to produce polymers with well-defined primary structures.
We focused our attention on the precision controlled/living polymerization and copolymerization of
bunch of naturally-derived renewable monomers, which are comparable to the conventional
petrochemical common vinyl monomers such as olefins, styrenes, and (meth)acrylates.1-9 Here, I will
especially discuss the polymerizations of the functional monomers, which could be prepared via
chemical modification of abundantly produced natural products, such as terpene, glycerol, cinnamic
and itaconic derivatives.
References
1. Satoh, K. Polymn. J. 2015, 47, 527.
2. Satoh, K.; Kamigaito, M. et al. Green Chem. 2006, 8, 878; Polym. Chem. 2014, 5, 3222.
3. Satoh, K.; Matsuda, M.; Kamigaito, M. J. Am. Chem. Soc. 2010, 132, 10003; Macromolecules 2013,
46, 5473; J. Polym. Sci., Part A, Polym. Chem. 2013, 51, 1774.
4. Masataka, O.; Satoh, K.; Kamigaito, Angew. Chem. Int. Ed. 2017, 56, 1789.
5. Satoh, K.; Saitoh, S.; Kamigaito, M. J. Am. Chem. Soc. 2007, 129, 9586.
6. Nonoyama, Y.; Satoh, K.; Kamigaito, Polym. Chem. 2014, 5, 3189.
7. Satoh, K.; Lee, D.-H.; Nagai, K.; Kamigaito, M. Macromol. Rapid Commun., 2014, 35, 161.
8. Miyaji, H.; Satoh, K.; Kamigaito, M. Angew. Chem. Int. Ed., 2016, 55, 1372.
9. Takeshima, H.; Satoh, K.; Kamigaito, M. Macromolecules 2017, 50, 4206
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IL7 High-performance Bio-based Polymers Derived from Aromatic Amino Acids
Tatsuo Kaneko*
Graduate School of Advanced Science and Technology, Energy and
Environment Area, Japan Advanced Institute of Science and
Technology
kaneko@jaist.ac.jp
Weight-saving of industrial materials is indispensable for
establishme nt of green-sustainable societies. Replacement of hard
and heavy materials into light plastics is very effective on
lightening. Most plastics, however, have lower thermal and
mechanical performances than the heavy materials. Especially,
transparent plastics such as polycarbonates and
polymethylmethacrylate are expected to alternate glass materials
but their thermomechanical performances were too low to apply in
wide fields of electronics and optics. Conventional bioplastics, a
series of aliphatic polyesters, such as polyhydroxyalkanoates and
poly(lactic acid) showed high transparency but low mechanical
performances, either. Actually most of strong plastics are partially
crystallized to reduce the transparency. In order to solve the
dilemma, we have tried to prepare new amorphous bioplastics
comprising rigid aromatic backbones. Here we report 4-
aminocinnamic acid (4ACA) which was bioavailable by a microorganismal engineering. The
photodimer of 4ACA was prepared via [2+2] cycloaddition, which is a kind of biological dianilines.
The dianilines were indispensable for preparation of the aromatic polyamide and polyimide but
generally were very difficult to produce by a direct method of fermentation. The biodianilines were
polymerized with diacids to give aromatic polyamides and with tetraacid dianhydrides to give aromatic
polyimides. Especially the polyimides derived from the photodimer and cyclobutanetetracarboxylic
dianhydrides showed a good thermomechanical performance, and additionally showed a high
transparency [1]. Besides we synthesized acetylated 4ACA photodimer as a bio-derived diacid, and
then the diacid was polycondensed with the dianilines to produce new biopolyamides with truxillamide
backbone comprising rigid phenylenes and their connecting cyclobutanes. Cyclobutanes sandwiched
by two phenylene rings can behave as a molecular spring and rigid structure as a result of
tautomerization, The molecular spring produced ultra-strong and transparent polyamides having
higher mechanical strength than heavy materials such as glasses [2]. This work was made under a partial
financial support from Grant-in-Aid for Scientific Research (B) (15H03864), and JST ALCA
References [1] Suvannasara, P; Kaneko, T. et al. Macromolecules 2014, 47(5), 1586. [2] Tateyama, S ; Kaneko,
T. et al. Macromolecules 2016, 49(9), 3336.
Scheme 1. Representative structure of biopolyimide and biopolyamide prepared here from amino acid
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IL8 Development of antimicrobial films for food packaging application Noreen Grace Fundador*, Queenie Clarin, Elizabeth Velasco and
Aleyla de Cadiz
College of Science and Mathematics, University of the Philippines
Mindanao, Tugbok, District, Davao City 8000, Philippines
*Email: nvfundador@up.edu. ph
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This research aimed to develop antimicrobial films using naturally occurring polysaccharides and
antimicrobial agents which are Generally Recognized as Safe (GRAS). In our study, we isolated durian
starch (DS) from durian seeds by aqueous extraction with 0.5% NaHSO3. The percent yield and purity
of the starch were 11.42% and 42%, respectively. Durian starch-carrageenan (DS-CG) blend films
containing different concentrations of carvacrol were prepared. The antimicrobial activity of the DS-
CG/carvacrol films was evaluated against S. aureus using disk diffusion assay. Results showed that
the zones of inhibition increased with increasing concentration of carvacrol indicating that carvacrol
is effective against S. aureus. Films containing 8% carvacrol showed significantly larger inhibition
zone sizes of up to 15.89 mm. The effectiveness of the films was also tested on commercial durian
candy. Films containing 8% carvacrol were found to significantly decrease the microbial count of the
food sample from 4.52 to 3.88 log CFU·mL-1 (0.63 log reduction) after 8 h of storage at 4 oC. After 24
h of storage, the microbial count was reduced to 3.05 log CFU·mL-1 (1.5 log reduction). In another
study, we prepared sago starch-sodium alginate (SS-SA) blend films containing different of
concentrations of nisin to control the growth of S. aureus. At 10% nisin, the measured zone of
inhibition was 10.72 mm. The antimicrobial efficacy of the film was also evaluated on commercial
processed cheese inoculated with S. aureus. A reduction in the microbial count by 2.03 and 2.75 log
count were observed after 6 and 18 h storage, respectively. These results suggest that the film was able
to prevent the growth of S. aureus on the surface of the cheese. The findings of these studies highlight
the potential of the films as an antimicrobial biodegradable packaging material that can enhance
microbial safety of food.
Table 1. S. aureus count of durian candy covered with DS-CG films containing 8% carvacrol after
different storage times at 4 °C.
Treatment Initial Log
CFU·mL-1
S. aureus count1 (log CFU·mL-1)
Storage Time2
8 h 16 h 24 h
0% carvacrol 4.52 ± 0.01W
4.24 ± 0.03bX 3.98 ± 0.12bY 3.84 ± 0.05bY
8% carvacrol 3.88 ± 0.14cX 3.37 ± 0.26cY 3.05 ± 0.39cZ
1Treatment means within a column followed by the same letter are not significantly different at α=0.05. 2W-Z: compares significant differences between initial and different storage times.
mailto:nvfundador@up.edu.%20ph
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IL9 Amino Acids Make Polyhydroxyalkanoate Copolymers More Diverse
Takeharu Tsuge1 1Dept. of Materials Science and Engineering, Tokyo Institute of
Technology
tsuge.t.aa@m.titech.ac.jp
Nowadays, over 150 different building blocks are known for polyhydroxyalkanoate (PHA). Poly[(R)-
3-hydroxybutyrate], P(3HB), is the most common type of PHA but P(3HB) is brittle and has poor
flexibility due to high crystallinity. Therefore, 3HB-based copolymers are now recognized as a
practical material.
P(3HB-co-3-hydroxyvalerate), P(3HB-co-3HV), is the first developed copolymer; however, 3HB and
3HV are co-crystallized each other, thus, P(3HB-co-3HV) still has low flexibility. P(3HB-co-3-
hydroxyhexanoate), P(3HB-co-3HHx), has more flexible than P(3HB-co-3HV), and has attracted a
great deal of industrial attention in recent times.
Other than linear side-chain monomer units, amino acids can potentially provide diverse side-chain
monomers such as branched side-chain and aromatic side-chain. For example, leucine and valine can
provide 3-hydroxy-4-methylvalerate (3H4MV) unit, which has branched side-chain. Phenylalanine is
also potential precursor for 3-hydroxy-3-phenylpropionate (3H3PhP) unit, which has phenyl side-
chain.
These 3HB-based copolymers, P(3HB-co-3H4MV) and P(3HB-co-3H3PhP), exhibit better material
properties than conventional P(3HB) and P(3HB-co-3HV). Additionally, almost of all PHA-producing
bacteria possess complete amino acid biosynthesis pathways, thus, it would be possible to conduct
metabolic engineering of amino acid biosynthesis pathway for supplying such amino acid-derived
monomers. This presentation will cover mainly resent advantages in amino acid-derived PHA
synthesis.
Reference:
Watanabe, Y., Ishizuka, K., Furutate, S., Abe, H., & Tsuge, T. Biosynthesis and characterization of
novel poly(3-hydroxybutyrate-co-3-hydroxy-2-methylbutyrate): thermal behavior associated with α-
carbon methylation. RSC Adv., 5, 58679-58685 (2015).
Mizuno, S., Katsumata, S., Hiroe, A., & Tsuge, T. Biosynthesis and thermal characterization of
polyhydroxyalkanoates bearing phenyl and phenylalkyl side groups. Polym. Degrad. Stab., 109, 379-
384 (2014).
Hiroe, A., Ishii, N., Ishii, D., Kabe, T., Abe, H., Iwata, T., & Tsuge, T. Uniformity of monomer
composition and material properties of medium-chain-length polyhydroxyalkanoates biosynthesized
from pure and crude fatty acids. ACS Sustainable Chem. Eng., 4, 6905-6911 (2016).
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IL10 Bio-plastic in Indonesia; Current Status and Challenges
Myrtha Karina, Lucia Indrarti, Rike Yudianti and Indriyati
Research Unit for Clean Technology, Indonesian Institute of
Sciences, Jalan Cisitu 21/154D, Bandung 40135, Indonesia
myrtha.karina.sancoyorini@lipi.go.id
Plastic consumption in Indonesia is still relatively low per-capita basis around 20 kg/ per year,
compared to 35 kg in Malaysia or Thailand and 40 kg in Singapore. However, it generated a huge
amount of wastes. In order to promote environmental conservation, the government of Indonesia issued
regulations namely Act No. 18/2008 concerning Solid Waste Management and Act No. 32/2009
concerning Environmental Protection and Management. The two acts were issued together with the
assistance through training and education, technical support, as well as R & D to support 3 R
implementation. Unfortunately, neither the solid waste management act nor the 3R implementation is
not yet showed significant impact due to, partly, lack of facilities and low cultural environmental
awareness. In contrast, establishment of new petrochemical industry is approvable by the government.
This situation caused an environmentally problem since the origin of plastic is not degradable and and
most plastics end up in municipal land fill sites. In addition, there is one issue of the big global
repercussions in Indonesia namely “plastic waste dumped into the sea” whereas plastic waste in the
ocean is a serious problem.
With the increasing of environmental problem awareness, degradable plastics have received
substantial attention in scientific literature as well as industries. Bio-plastic such as starch-based and
oxo–degradable is produced by several private companies and was launched into the market. Since the
price is costly, the usage of bio-plastic is still limited, for instance in well known super market in big
cities. On the other hand, Indonesia is a country rich with natural resources of which potential bio-
plastic production. Since plastics are used in almost everywhere and its demand rises every year, this
creates challenges to produce biodegradable bio-plastics made from renewable resources.
This paper aims to elaborate the challenges of research opportunities on bio-plastic carried out in
Indonesia using the sustain natural resource.
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IL11 Understanding PLA-PBS copolymer: A multi-functional additive for PLA/PBS blend and its tunable molecular assembly
Raksit Supthanyakul,1 Narin Kaabbuathong2, Suwabun
Chirachanchai*1 1The Petroleum and Petrochemical College, Chulalongkorn
University, Pathumwan, Bangkok, 10330 Thailand 2PTT Research and Technology Institute, PTT Public Company
Limited, Phra Nakhon Si Ayutthaya, 13170, Thailand
*E-mail: csuwabun@chula.ac.th
Poly(lactide) (PLA) is the most potential renewable resource-based polymer with a cost performance,
reliable mechanical properties and industrial scaled production. However, PLA is still limited by its
brittleness, low heat distortion temperature, and slow crystallization rate. The blending PLA with other
biodegradable synthetic polyester, especially poly(butylene succinate) (PBS) is accepted for its
performances to improve PLA in terms of flexibility, melt processability, good thermal stability and
chemical resistance. However, the main problems of PLA and PBS blends are the immiscibility based
on the crystallization-induced phase separation and poor interfacial adhesion between two phases.
Therefore, the compatibilizers for PLA/PBS blends are important and they were variously proposed.
In the past, many compatibilizers, such as dicumyl peroxide, lysine triisocyanate, lysine diisocyanate,
and organoclay were reported for their roles in enhancing the compatibility and the toughness. To our
viewpoint, the copolymer of PLA and PBS is a potential compatibilizer because it contains both PLA
and PBS structures to favor the miscibility. Up to the present, the preparation of PLA-co-PBS including
the use as compatibilizer have been reported, however, the copolymer structure and the effect of the
structure to the compatibility have not yet been focused.
Herein, we demonstrate the preparations of random poly(butylene succinate-co-ʟ-lactic acid)
(rPBSL) and triblock poly(ʟ-lactide-b-butylene succinate-b-ʟ-lactide) (PLLA-b-PBS-b-PLLA) and the
effects on miscibility, nucleation, and the balance of crystalline-amorphous phases. The work also
clarifies how the films obtained from PLA blending with PBS containing rPBSL and PLLA-b-PBS-b-
PLLA maintain the clarity and extends the discussion to understand the functions of PLLA-b-PBS-b-
PLLA based on the comparative studies between PLLA-b-PBS-b-PLLA and rPBSL. Moreover, the
presentation covers a comb-like copolymer based on poly(2-hydroxyethyl methacrylate) (PHEMA)
backbone with PLLA side chains and PBS terminals, and its tunable molecular assembly based on the
solvent polarity and transition temperature.
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19
IL12 High performance bio-based plastics from
natural and unnatural polysaccharide
Tadahisa Iwata
The University of Tokyo, E-mail: atiwata@mail.ecc.u-tokyo.ac.jp
The increasing environmental and economic concerns on the utilization of petrochemicals have led
researchers to rely on plant biomass as a feedstock for the synthesis of polymeric materials. Recently,
our group succeeded to synthesize new thermoplastics from polysaccharides such as xylan [1],
glucomannan [2,3], curdlan [4], pullulan [5,6], etc by esterification and found interesting thermal,
mechanical, optical properties (Figure 1). Xylan is the most abundant hemicellulose with mainly -
(1→4) linked xylose. Konjac glucomannan (GM) is isolated from tubers of Amorphophallus konjac
plants and consists of -(1→4) linked D-glucose and D-mannose residues and the molecular ratio of
glucose to mannose has been reported to be ca. 1.6. Curdlan is a linear polysaccharide with -(1→3)
linked glucose produced by Alcaligenes faecalis. Pullulan is a water-soluble extracellular
polysaccharide produced by strains of fungus Aureobasidium pullulans, consisting of a chain of
maltotriose units that alternate regularly between -(1→6) linkages. In this paper, xylan, glucomannan,
curdlan and pullulan ester derivatives are synthesized and thermal and mechanical properties are
investigated. Furthermore, in the case of xylan ester derivatives, a possibility as bio-based nucleating
agents for PLLA and PDLA is presented [7,8].
More recently, we succeeded the one-pot synthesis and development of unnatural-type bio-based
polysaccharide, -1,3-glucan [9]. The synthesis can be achieved by in vitro enzymatic polymerization
with GtfJ enzyme, one type of glucosyltransferase, cloned from Streptococcus salivarius ATCC 25975
utilizing sucrose, a renewable feedstock, as a glucose monomer source, via environmentally friendly
one-pot water-based reaction. Furthermore, ester derivatives of -1,3-glucan were synthesized and
characterized [10].
References: [1] N. G. Fundador, et al., Polymer, 53, 3885 (2012). [2] Y. Enomoto-Rogers, et al.,
Carbohydr. Polym., 101, 592 (2014). [3] T. Danjo, et al., Polym. Degrad. Stab., 109, 373 (2014). [4]
Marubayashi, et al., Carbohydr. Polym., 103, 247 (2014). [5] Y. Enomoto-Rogers, et al., Euro. Polym.
J., 66, 470 (2015). [6] T. Danjo, et al., Scientific Reports, 7, 46342 (2017). [7] N. Fundador, et al.,
Polym. Degrad. Stab., 98, 1064 (2013). [8] N. Fundador and T. Iwata, Polym. Degrad. Stab. 98, 2482
(2013). [9] S. Puanglek, et al., Scientific Reports 6, 30479 (2016). [10] S. Puanglek, et al.,Carbohydr.
Polym. 169, 245–254 (2017).
http://www.sciencedirect.com/science/article/pii/S0144861717303880http://www.sciencedirect.com/science/journal/01448617/169/supp/C
-
General Lecture
(GL1-GL13)
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20
GL1
Supra-Polysaccharide Recognizes Geometric Spaces Under Drying Environment
Kosuke Okeyoshi,1 Maiko Okajima,1 and Tatsuo Kaneko 1 1 Japan Advanced Institute of Science and Technology (JAIST)
1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan
E-mail: okeyoshi@jaist.ac.jp
Living organisms under drying environments build anisotropic structures and exhibit directionality
through self-integration of biopolymers. However, the process of macro-scale assembly is still
unknown. Here we introduce a dissipative structure through a non-equilibrium process between
hydration and deposition in the drying of a polysaccharide liquid crystalline (LC) solution. By
controlling the geometries of the evaporation front in a limited space, multiple nuclei emerge to grow
vertical membrane walls with macroscopic orientation (Figure 1). Notably, the membranes are formed
through rational orientation of rod-like microassemblies along the dynamic three-phase contact line.
We use a polysaccharide, sacran [1], extracted from one of the cyanobacteria, which has a
megamolecular weight (Mw > 107 g·mol-1) and polymeric assembles of huge rod-like microdomains
(~1 µm diameter and > 20 µm length) as the LC structural unit [2]. In the non-equilibrium state via
drying, a dissipative structure is ultimately immobilized as a macroscopically partitioned space by
multiple vertical membranes [3]. We foresee that such membranes will be applicable to soft
biomaterials with directional controllability, and the macroscopic space partitionings will aid in the
understanding of the space recognition ability of natural products under drying environments.
Figure 1. Drying-induced polymer deposition to form vertical membrane walls and macro-space
partitioning. The schematic (a) and the images acquired under cross-polarized light (b).
[1] T. Kaneko, et al., Macromolecules 41, 4061 (2008). [2] K. Okeyoshi, et al., Biomacromolecules
17, 2096 (2016). [3] K. Okeyoshi, et al., Scientific Reports, in press.
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21
GL2
Thermoplastic starch-based materials for packaging applications
Rangrong Yoksan,*1,2 1Department of Packaging and Materials Technology, Faculty of Agro-Industry, Kasetsart
University, Bangkok 10900, Thailand 2Center for Advanced Studies for Agriculture and Food, Kasetsart University, Bangkok
10900, Thailand
e-mail address: rangrong.y@ku.ac.th
Thermoplastic starch (TPS) is a bio-based material derived from the plasticization of starch, which is
cheap, non-toxic, naturally abundant, renewable, biodegradable and compostable, under applying heat
and shear force. Although TPS possesses good gas barrier property, its high water/moisture
absorption leads to poor mechanical and barrier properties. In addition, TPS has easily thermal
deformation and high mold shrinkage. These characteristics limit TPS utilization. Blending TPS
with other relatively hydrophobic polymers, such as poly(lactic acid) (PLA), polyethylene (PE),
polypropylene (PP), chitosan, etc. or reinforcing with natural fibers are alternatives to reduce moisture
sensitivity of TPS or improve its properties with reasonable cost performance. Blending TPS with
PLA is one of our goals to obtain the completely bio-based and biodegradable materials for disposable
packaging applications. To reduce the use of petroleum-based plastics, TPS is also blended with PE
and/or PP. TPS-based materials can be converted into both flexible packaging film and rigid
packaging using blown film extrusion and injection molding processes, respectively. This
presentation demonstrates the approaches to improve TPS properties and also proposes the feasible
applications of TPS-based materials.
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22
GL3 Biodegradation of polyhydroxyalkanoate copolymer films as
monitored using reactive pyrolysis-gas chromatography
Siti Baidurah,*1 Kumar Sudesh,2 and Yasuyuki Ishida3
1 School of Industrial Technology, Universiti Sains Malaysia, 11800, Minden, Penang,
Malaysia (sitibaidurah@usm.my) 2 School of Biological Sciences, Universiti Sains Malaysia, 11800, Minden, Penang,
Malaysia. 3 Department of Biological Chemistry, College of Bioscience and Biotechnology, Chubu
University, 1200 Matsumoto-cho, Kasugai 487-8501, Japan.
The compositional analysis of polyhydroxyalkanoate (PHA) copolymer films is important
since their chemical composition is closely related to various properties such as biodegradation rate,
crystallinity and transparency. Various analytical approaches, such as spectroscopic methods and
conventional chromatographic techniques, have been used to achieve this goal. Among them, nuclear
magnetic resonance (NMR) spectroscopy and post-transmethylation gas chromatography (GC) are the
most utilized characterization techniques. However, these two techniques are not always applicable
for routine analysis because of the relatively large amount of sample and fairly long measuring time
including that required for sample preparation.
Currently, reactive pyrolysis-gas chromatography (Reactive Py-GC), also known as thermally
assisted hydrolysis and methylation-GC (THM-GC), has become a useful technique for compositional
analysis of various polymers. In this research, we applied the reactive Py-GC technique to the
compositional analysis of PHA copolymer including poly(3-hydroxybutyrate-co-3-hydroxyvalerate)
[P(3HB-co-3HV)] and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) [P(3HB-co-3HHx)].
Acknowledgement: This work was supported by Universiti Sains Malaysia Short Term Grant
(304/PTEKIND/6313277) and RUI (1001/PTEKIND/8011022).
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23
GL4 Long-term stability of flexibility of microbial poly(lactate-co-3-hydroxybutyrate) films
Daisuke Ishii,*1,3,5,6 Kenji Takisawa,2,4,6 Ken’ichiro Matsumoto,2,6 Toshihiko Ooi,2,6
Takaaki Hikima,5 Masaki Takata,5 Tadahisa Iwata3,5,6 and Seiichi Taguchi1,2,6 1Department of Chemistry for Life Sciences and Agriculture, Faculty of Life Sciences,
Tokyo University of Agriculture, Japan (e-mail: di206176@nodai.ac.jp) 2Division of
Applied Chemistry, Graduate School of Technology, Hokkaido University, Japan 3Department of Biomaterial Sciences, Graduate School of Agricultural Sciences, The
University of Tokyo, Japan 4Department of Environmental Science and Education,
Faculty of Home Economics, Tokyo Kasei University, Japan 5SPring-8 Center, RIKEN
Institute, Japan 6 JST-CREST, Japan
Poly[(R)-lactate-co-(R)-3-hydroxybutyrate]s [P(LA-co-3HB)s] are biobased polyesters with flexible
properties and transparency efficiently synthesized by engineered Escherichia coli (Fig. 1).[1] Here,
we aimed at optimizing the monomeric composition of the copolymer in terms of its flexibility, and
elucidating structural features contributing to their mechanical properties. The LA content was
successfully regulated in the range of 6 to 66 mol% by combination of metabolic and enzyme
engineering approaches. The copolymers with higher LA content showed decreasing melting point
from 160 to 125 ºC, but increasing glass transition from 7 to 27 ºC (Table 1). Crystallinity of the as-
cast film, that was mainly attributed to the crystallization of 3HB unit, also decreased with the
increasing LA content. Owing to the combined effect of these parameters, the highest elongation to
break (approximately 400%), which is comparable to that of polyethylene, was obtained for the
copolymers with LA fraction of 33 mol%. The high flexibility was maintained in most of the
copolymers. Notably, P(21.0 mol% LA-co-3HB) retained its high elongation at break (about 300%)
even after 5-months storage (Fig. 2). These results demonstrate that introduction of LA units into the
polymer chain effectively and stably inhibited the crystallization of 3HB units.
[1] Yamada, M. et al., J. Biotechnol., 2011, 154, 255.
Table 1. LA content and thermal property values of P(LA-co-3HB)s
LA (mol%) 6 21 33 40 48 66
Tg (ºC) 7 13 22 27 26 25
Tm (ºC) 157 157 148 148 125 NDa
a Not detected.
Fig. 1 Transparency of
P(21 mol% LA-co-3HB) film
Fig. 2 Stress-strain curves of P(21 mol% LA-co-3HB) film
after 2-week or 5-month storage.
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24
GL5
Linear and Star-shaped Copolymers for Improving PLA Toughness Chantiga Choochottiros,* and Vachiravit Chalermpanaphan Department of Materials Science, Faculty of Science, Kasetsart University, Bangkok
10900, Thailand.
*chantiga.c@ku.ac.th
Polylactic acid (PLA) is a biodegradable thermoplastic polyester. It has excellent properties to
compete with petroleum-based polymers. However, it has limitations to overcome which are brittle
and low thermal resistance. Our approach is to develop copolymers to improve toughness of PLA
including minimum effect of incompatibility between additive and PLA matrix. Rubbery polymers
are good candidates for softening material. Star-shaped copolymers with rubbery biodegradable
polymer such as polycaprolactone (PCL) as core and PLA as shell to provide miscibility to PLA
matrix including remain optical transparency of PLA. For linear copolymers, we imitated
polybutylene succinate (PBS) by providing unsaturated functional group along copolymer chains.
The unsaturated PBS-PLA copolymer was synthesized. This copolymer is not only rubbery
copolymer but also has unsaturated functional groups for further modification such as crosslinking.
We expect that this novel copolymer may improve toughness including thermal resistance of PLA.
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25
GL6 Stimuli responsive polymeric materials via host-guest interactions
Yoshinori Takashima,1 1 Department of Macromolecular Science, Graduate School of Science, Osaka University
Molecular recognition chemistry and supramolecular chemistry
have received much attention, owing to their effects on catalytic
activity, molecular switches, and materials. Stimuli-responsive
supramolecular polymers is relevant not only for biological
functions but also for a range of other applications. Our research
group has employed cyclodextrins (CDs) as host molecules. In
this presentation, I would like to introduce our studies to realize
sol-gel switching, self-healing, adhesion control, and contraction-
expansion properties through the formation of inclusion
complexes with CDs.
Adhesion and self-healing material: First, adhesion between
the host hydrogel with βCD and the guest hydrogel with an
adamantyl (Ad) group was investigated. The βCD hydrogel
selectively adheres to the Ad guest hydrogel without mismatching.
Next, we prepared effective self-healing materials based on
βCD and Ad units. When two cut surfaces were brought into
contact, the two pieces adhered. The adhered materials showed
almost complete recovery of the initial material strength. The
recovery ratio of the rupture strength increased with adhesive time.
Interestingly, only cut surfaces showed a self-healing property,
whereas uncut surfaces did not.
Photoresponsive materials: Two structural approaches may
realize supramolecular actuators through host–guest interactions:
a method with a linear main chain and one with a side chain in the
polymer structure (Fig. 3). We have prepared photo responsive
supramolecular actuators by integrating host–guest interactions on
the polymer side chains (Fig. 3a). Another supramolecular
hydrogels containing CD-based [c2]daisy chains as crosslinkers
contract and expand through photoresponsive sliding motions of
the [c2]daisy chain (Fig. 3b).
References (1) Harada, A.; Kobayashi, R.; Takashima, Y.; Hashidzume, A.; Yamaguchi,
H., Nat. Chem. 2011, 3, 34-37.
(2) Nakahata, M.; Takashima, Y.; Yamaguchi H.;Harada, A., Nat. Commun.
2011, 2, 511.
(3) Kakuta, T,; Takashima, Y.; Nakahata, M.; Otsubo, M,; Yamaguchi, H.;
Harada, A. Adv. Mater. 2013, 25, 2849-2853.
(4) Miyamae, K.; Nakahata, M.; Takashima, Y.; Harada, A. Angew. Chem.
Int. Ed. 2015, 54, 8984-8987.
(5) Takashima, Y.; Hatanaka, S.; Otsubo, M.; Nakahata, M.; Kakuta, T.;
Hashidzume, A.; Yamaguchi, H.; Harada, A. Nat. Commun. 2012, 3,
1270.
(6) Iwaso, K.; Takashima, Y.; Harada, A. Nat. Chem. 2016, 8, 625-632.
(7) Nakahata, M.; Takashima, H.; Harada, A. et. al. Chem. 2016, 1, 766-775.
(8) Harada, A.; Takashima, Y.; Nakahata, M. Acc. Chem. Res. 2014, 47,
2128.
Figure 1. Supramolecular materials based on host-guest
interactions with cyclodextrins (CDs).
Figure 2. Self-healing materials based on host-guest
interactions. Chemical structures (a) and healing
behavior (b).
Figure 3. Supramolecular actuators using CD derivatives.
These supramolecular actuators show macroscopic
contraction–expansion and flexing behaviors.
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26
GL7
Molecular Recognition by Cyclodextrin Derivatives in Nonpolar Media
Toshiyuki Kida
Department of Applied Chemistry, Graduate School of Engineering, Osaka University,
Suita, Osaka 565-0871, Japan e-mail: kida@chem.eng.osaka-u.ac.jp
Cyclodextrins (CDs) and their derivatives have played a crucial
role in various fields including supramolecular chemistry and
analytical science due to their unique properties to form inclusion
complexes with a variety of molecules. However, in most cases,
inclusion complex formation with CD hosts has been limited to
aqueous media and several kinds of polar organic media. On the
other hand, the effective guest inclusion by CD hosts in nonpolar
media has not been achieved yet, because the enormous amounts of
nonpolar solvents become a strong competitor for inclusion within
the CD cavity. Recently, we found that 6-O-modified -CDs (Fig.
1), such as heptakis(6-O-triisopropylsilyl)--CD (TIPS--CD) and
heptakis(6-O-tert-butyldimethylsilyl)--CD (TBDMS--CD),
effectively formed inclusion complexes with polychlorinated
aromatic compounds1 and pyrene2 in nonpolar solvents. The X-ray
crystalline structure of the inclusion complex between TIPS--CD
and pyrene from the benzene solution shows that a pyrene molecule
is incorporated within the dimer cavity formed by two TIPS--CD
molecules (Fig. 2). The pyrene molecule forms a sandwich-type
complex with two benzene molecules through - interactions, and
is located at the center of the capsule cavity. We also demonstrated
that a high chiral recognition of aromatic amines is realized by
utilizing inclusion within the cavity of the supramolecular dimer
formed by an assembly of TIPS--CD in nonpolar solvents.3,4 In
particular, an extremely high binding selectivity for (S)-1-(1-
naphtyl)ethylamine ((S)-1) over the corresponding (R)-isomer was
achieved.3 A crystallographic study of the complex between the
supramolecular dimer and (S)-1 obtained from the benzene solution
shows that hydrogen bonding between the guest and CD host as
well as the interactions between the guest and the solvent molecules
inside the capsule cavity play crucial roles in enantioselective guest
inclusion (Fig. 3). This presentation will deal with the complex
formation between various CD derivatives including CD polymers
and guest molecules in nonpolar media.
References
1) T. Kida et al., Org. Lett. 2009, 11, 5282. 2) T. Kida et al., Org.
Lett. 2011, 13, 4570. 3) T. Kida et al., J. Am. Chem. Soc. 2013, 135, 33714. 4) H. Asahara et al.,
Tetrahedron 2014, 70, 197.
O
O
OH
OH
O
7
TBDMS--CD: R = SitBuMe2
R
TIPS--CD: R = Si(i-Pr)3
Figure 1. Chemical structures
of CD hosts.
Figure 2. Crystal structure of TIPS--CD–pyrene inclusion complex.
TIPS--CD
benzene
pyrene
benzene
TIPS--CD
benzene
pyrene
benzene
Figure 3. Crystal structure of TIPS--CD–(S)-1 inclusion complex.
TIPS--CD
H2O
TIPS--CD
(S)-1
benzene
benzene
TIPS--CD
H2O
TIPS--CD
(S)-1
benzene
benzene
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27
GL8
Thermoplastic natural rubber bio-composites: fiber types, fiber treatments and mechanical properties Azizah Baharum,*1,2 Mohd Razi Mat Piah,2 Wan Zarina Wan Mohamed 2,3 and Nurzam
Ezdiani Zakaria 2,4 1Polymer Research Center, Faculty of Science and Technology, National University of
Malaysia, 43600 UKM Bangi, Selangor, Malaysia 2School of Chemical Sciences and Food Technology, Faculty of Science and Technology,
Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia 3Faculty of Science and Biotechnology, Universiti Selangor, 45600 Bestari Jaya Selangor,
Malaysia. 4Food Processing and Packaging Program, Food Science Technology Research Centre,
Malaysian Agricultural of Research and Development Institute, P.O Box 12301 General
Post Office, 50774 Kuala Lumpur, Malaysia
E-mail: azeiss@ukm.edu.my
Bio-composites consisting of one or more phases derived from natural resources such as mengkuang
fiber (MKF), Sansevieria trifasciata fiber (STF) and natural rubber (NR). The addition of MKF, STF
and NR into thermoplastic resin such as high density polyethylene (HDPE) were believed to increase
the biodegradability and modulus of the composites produced. The physical and mechanical properties
of NR/HDPE/Natural fiber bio-composites were found to be dependent on the preparation parameters
such blend composition, processing parameters and compatibilizer used. The bio-composites was
prepared via melt blending by using internal mixer (Haake Rheomix 600). The optimum processing
parameters identified were temperature at 135 C, rotor speed of 45 rpm, and 12 minutes processing
time. 20% was found to be the optimum filler loading of MKF and STF with 40/60 NR/HDPE matrix
composition. About 10% improvements were achieved in tensile strength of MKF filled bio-
composites as compared to the unfilled NR/HDPE blend. However, the tensile modulus and impact
strength decreased by about 40% and 26% respectively. On the other hand, adding STF decreased the
NR/HDPE performance showing that STF acted only as an inert filler. Treatments were done on the
fibers using Hexadecyltrimethoxysilane (HDS) or liquid natural rubber (LNR) and liquid epoxidized
natural rubber (LENR) to improve fiber-matrices interface interaction. The results showed that HDS
has improved about 20 to more than 60% of the mechanical properties of NR/HDPE/MKF and more
than 60% of the mechanical properties of NR/HDPE/STF bio-composites while LNR and LENR
treatments did not act as compatibilizer with NR/HDPE/MKF but only as plasticizer in the bio-
composites by resulting decrement in the mechanical properties. However, comparing LNR with
LENR treatments, MKF bio-composites treated with LNR showed better mechanical results due to the
similarity of the structure between LNR and NR resulting better homogeneity in the bio –composites
obtained. These results were supported by morphology examination via FESEM and functional group
determination via FTIR. The MKF was found to have rough surfaces and micropores, producing good
mechanical interlocking and adhesion between fiber and matrix interphase compared to STF shows
smooth surfaces that does not contribute in effective interaction between fiber-matrices interphase.
Thus for conclusion, the MKF fiber treated with HDS is a potential filler for NR/HDPE blends with
enhanced mechanical properties.
mailto:azeiss@ukm.edu.my
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28
GL9
Biodegradation of Aliphatic Polyesters in Seawater
Atsuyoshi Nakayama, Norioki Kawasaki, and Naoko Yamano
National Institute of Advanced Industrial Science and Technology (AIST), Osaka, Japan
a.nakayama@aist.go.jp
Biodegradable polymers are expected to be alternative materials to solve the environmental pollution
caused by the wastes of bioresistant synthetic polymers. Improvement of reliability of biodegradation
is indispensable to increase the use. Conceivable approaches are control of biodegradation rate by
molecular design and investigation of environmental parameters on biodegradation. Recently,
diffusion of microplastics into the sea is a serious issue to solve, and the biodegradable polymers for
marine use should also be reviewed. Aliphatic polyesters were well-known to be biodegradable in soil,
in compost, and by activated sludge, but reports of biodegradation in the sea are not so much. These
days, the standard procedure for aerobic biodegradation in a seawater was published. However, there
are not a few unknown pneumonia and factors to consider on biodegradation behavior in a seawater.
For example, topography of shoreline, outflow of river water, the tide ebbs and flows, salinity, season,
seawater temperature should be considered. In this paper, biodegradation of various polyesters in a
seawater by lab and field tests was mentioned, and some factors on biodegradation have be clarified.
As for BOD lab test, sea waters were collected from surface of sea in various places in Osaka bay
and other places. The test was performed in closed system, and consumption of O2 was measured.
P3HB showed rapid biodegradation with all of the seawater. The biodegradation activity of the sea
water was dependent on the place. For example, Seawaters at Osaka port show high biodegradability
and seawaters in rural area shows low. In Osaka, the populations of bacteria are large compared to
those of rural. Biodegradation activity of seawater is likely to be associated with the pollution of water.
Examination temperature is also an important factor, that is, higher temp (27 C) showed better
biodegradation. In the cases of synthetic polyesters, PCL also degraded fast. However, PBSA which
is a popular biodegradable polymer was not always biodegraded by BOD method with sea water. PBS
and PBAT showed much slow biodegradation.
Solvent cast films were set into plastic containers, and they were immersed in a seawater under 1 to
1.5 meter depth. After 4 weeks, the weight loss of PHB film was about 90 %. On the contrary, the
biodegradation by BOD method for 4 weeks was around 50%. Some of the synthetic polyesters showed
obvious weight loss in field test, in contrast to the BOD results.
We will discuss the differences and several factors that influence biodegradation in the sea.
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29
GL10
Poly(lactic acid)-based Biocomposites from Agricultural Residues Suttinun Phongtamrug,1 Apirat Laobuthee,2 Amornrat Lertworasirikul,2
Chatchai Veranitisagul,3 and Sirisart Ouajai1 1Department of Industrial Chemistry, Faculty of Applied Science, King Mongkut’s
University of Technology North Bangkok, Bangkok 10800, Thailand 2Department of Materials Engineering, Faculty of Engineering, Kasetsart University,
Bangkok 10900, Thailand 3Department of Materials and Metallurgical Engineering, Faculty of Engineering,
Rajamangala University of Technology Thanyaburi, Pathumthani 12110, Thailand
Thailand is predominantly an agriculture-based country providing variety of agricultural products
including natural fibers. Research and development technology as well as related industries have been
grown up rapidly and generate a large amount of agro-industrial by-products including agricultural
waste and residues. Therefore, utilization of agricultural residues has been considered in various
application. Natural fibers, mainly composed of cellulose, have high strength and stiffness. They have
been used as reinforcements to enhance mechanical and thermal properties of composites. Based on
environmental concerns, biocomposites have received much attention due to lightweight, cost
effectiveness, and ecofriendliness. Considering polymer matrix in the viewpoint of biodegradability,
processability, and an industrial-scale production, poly(lactic acid) is the most promising candidate.
However, phase separation between poly(lactic acid) and natural fiber is possibly occurred which
resulted in decreasing mechanical property. Chemical treatments to improve miscibility are sometimes
needed. This presentation focuses on biocomposites based on poly(lactic acid) and agricultural
residues such as oil palm fiber, tea leaf, and wood powder. Chemical treatments, e.g., sodium
hydroxide, of the fibers have been carried out. The masterbatches of poly(lactic acid) and various
agricultural residues have been prepared and processed in different forms such as films, sheets, and
test specimens. Thermal property and mechanical property of the biocomposites are also investigated
for practical use.
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30
GL11
Development of Heat-resistant Polymeric Materials from Bio-based Chemicals
Hideki ABE1 1 Bioplastic Research Team, RIKEN Center for Sustainable Resource Science, Japan,
habe@riken.jp
Bio-based polymers have attracted industrial attention as environmentally friendly thermoplastics to
be used for a wide range of applications. We have promoted the basic research program to provide
novel high-performance and specific functional bio-based polymer materials.
According to the regulation manner of biopolymers, we have designed and synthesized the
molecules with precise sequence structure, so we call periodic copolymers. Until now, we have been
successfully obtained the periodic copolymers with high-thermo-resistance from biomass ester and
amide monomers. The periodic copolymers have melting temperatures over 200 °C, and the values
are significantly higher than those of random copolymers. Both the ester and amide units are
incorporated into the crystalline region, and the intermolecular hydrogen bond is formed between
neighboring amide groups in the crystallizing molecules. We also succeeded in producing the
alternating copolymers of lactic acid and 3-hydroxybutyric acid units. By selecting the combination
of enantiomers of chiral two monomeric units, the melting temperatures of alternating copolymers
were varied over a wide range. Especially, when each monomer with R-configuration was used, the
obtained alternating copolymer showed melting temperature at around 230 °C. The value was
remarkably higher than those of homopolymers. Thus, we demonstrate that the sequential regulation
of monomer units is one of excellent tools to express high performance for biomass polymers.
As second project, we embarked on the synthesis of novel bio-based acrylic resins from crotonic
acid and cinnamate derivatives. The organic acids such as super strong acids catalyzed the group
transfer polymerization of crotonic acid and cinnamate derivatives at a C-C double bond to give the
corresponding polymer molecules. The high-molecular-weight polymer of crotonic acid has higher
glass-transition temperature, compared with the general-purpose petrochemical acrylic resins.
Furthermore, I would like to introduce our resent topics on syntheses of aromatic resins from
degradation products of lignin. By using vanillin derivatives, the syntheses of aromatic polyesters,
polyurethanes, and polyamides were carried out. Taking account of decomposition temperature of
monomeric compounds, the polymerization conditions were optimized. As a result, the bio-based
aromatic polymers containing vanillin derivatives were obtained at high molecular weights
(Mw>50,000). Those aromatic polymers synthesized from the vanillin derivatives also revealed
higher heat-resistant properties.
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31
GL12
Structural Modification: From Bio-based Polymers to Functional Materials
Nonsee Nimitsiriwat,1 Apirat Laobuthee,2 Amornrat Lertworasirikul2 and
Chatchai Veranitisagul3 1Chemical Engineering Practice School, Pilot Plant Development and Training Institute,
King Mongkut’s University of Technology, Bangkok, Thailand 2Department of Materials Engineering, Faculty of Engineering, Kasetsart University,
Bangkok, Thailand 3Department of Materials and Metallurgical Engineering, Faculty of Engineering,
Rajamangala University of Technology Thanyaburi, Bangkok, Thailand
Due to great concerns on environmental problems and sustainability bio-based polymers have
continuously received enormous attention over the last few decades as alternatives in replacement of
commodity polymers, which are petroleum-based, non-biodegradable. However, their inferior
properties and relatively high costs have restricted their uses to a narrow range of applications, and
also commercial competitiveness. One way to promote their utilization and commercialization is by
making them into high-end products, particularly ones with special properties and functions. This talk
covers three on-going projects focusing on functionalization of poly(lactic acid) and chitosan to
provide specific properties and functions, including photochromic and luminescent, halochromic and
metal ion-selective. These functional materials are prepared by structural modification of the
corresponding polymers with appropriate compounds, either in bulk or surface, and then fabricated
into prototype products. Their specific properties and functions are also investigated in order to
evaluate their performances for practical uses.
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32
GL13
High Heat Resistant Biobased-polyamide (PA10T) – its features and Applications
Junichi Mii,1 Kazue Ueda*1 1Plastics Production & Development Department ,UNITIKA Ltd., enpla@unitika.co.jp
Unitika Ltd. has developed a high heat resistant polyamide “XecoT” derived from biomass resources,
and is aiming to expand the applications of this super engineering plastic.
As “XecoT” is a semiaromatic polyamide homopolymer (PA10T), it has excellent characters; high
melting temperature (315 degree C), high degree of crystallinity and high crystallization speed. These
properties of the resin provide the products with the features superior in heat resistance (high DTUL,
Thermal stability of tensile strength), abrasion, chemical resistance, water absorption, moldability
(high flow, capable of thin-walled molding), lead-free soldering, and so on.
For example, the components of electric and electronic devices and the automobile parts near engine
made of XecoT have received positive evaluation results. More details will be provided in the
presentation.
XecoTGF30%
PA9TGF30%
PA6TGF30%
Melting point [℃] 315 306 294
DTUL 1.8MPa [℃] 306 290 289
Crystallization Time (280℃-isothermal, DSC) *1 [℃] 0.26 1.78 -*2
Saturated water absorption (100℃,underwater) [%] 1.6 1.7 4.5
Dielectric breakdown strength [kV/mm] 40 28 28
Specific wear rate (suzuki-method, v.s S45C) [mm3/(km・kN)] 30 48 43
Degree of Biomass [%] 56 0 0
Property
Table 1. Properties of heat resistance polyamides
Fig 1. Chemical structure of XecoT
Fig 2. Temperature influence
of tensile strength (Glass reinforced)
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