Invited Lecture

(IL1-IL12)

8

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

9

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).

10

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).

11

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

12

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

Please add a

photo of

Presenting

author

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.

13

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

14

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

15

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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Presenting

author

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

16

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).

17

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.

18

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.

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)

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.

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.

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).

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.

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.

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.

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

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

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.

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.

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.

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.

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)