physicochemical characterization of biodegradable plastic
TRANSCRIPT
Journal of Environmental Engineering & Sustainable Technology JEEST Vol. 06 No. 02, November 2019, Pages 57-65 http://jeest.ub.ac.id
P-ISSN:2356-3109 E-ISSN 2356-3117 57
PHYSICOCHEMICAL CHARACTERIZATION OF BIODEGRADABLE PLASTIC
FROM UWI TUBER STARCH (DIOSCOREA ALATA) WITH SORBITOL AND
CMC (CARBOXYMETHYL CELLULOSE) AS PLASTICIZER ADDITION
Dina Wahyu Indriani1, Sumardi Hadi Sumarlan, Siti Munawaroh
1 Department of Agricultural Engineering, Faculty of Agricultural Technology, Universitas Brawijaya
Email : [email protected]
ABSTRACT
Uwi tubers (Dioscorea alata) are widely used as
biodegradable plastics materials because it
contains high starch content about 75,6 –
84,3%. Biodegradable plastics can be used as a
decent food wrapping. The purpose of this
research is to study the process of making
biodegradable plastics and analyze the effect of
a adding CMC (carboxymethyl cellulose) and
sorbitol plasticizers on the physicochemical
properties of biodegradable plastics from uwi
tuber starch with various parameters, solubility,
thickness, tensile strength, elongation, modulus
Young, compressive strength, biodegradability
and surface morphology of functional groups.
The making of plastic biodegradables is based
on the melt intercalation method. Uwi tuber
starch composition used was 5 grams, the
combination of CMC concentration used was 0
gram; 0,20 gram; 0,30 gram; 0,40 gram. While
the variations in the volume of sorbitol used are
2 ml, 3 ml, 4 ml, 5 ml. The results of this study
indicate that the additon of 0 gram CMC and 2
ml of sorbitol produce tensile strength values of
7,66 MPa, the best modulus Young is 5,52 MPa.
The compressive strength values is lower that is
equal to 0,150 kgf, the best elongation value is
at the addition of CMC 0,20 gram and sorbitol
5 ml that is equal to 39,44%. The concentration
of the CMC addition and sorbitol plasticizer on
biodegradable plastic affects physical
properties in SEM testing with the additon of 0
gram CMC and sorbitol 2 ml, which results are
denser when compared with the addition of 0,40
gram CMC and 5ml sorbitol. In the FTIR test,
there are C-O alcohol/ester/carboxylic acid/eter
functional groups in waves 1050-1300. Plastics
with the highest concentrations of CMC and
sorbitol need 7 days to be degraded.
Keywords: Biodegradable plastics, CMC, Uwi
Tuber, Sorbitol
1. INTRODUCTION
Almost every product that used plastic as
their packaging has advantages such as light
weight, strong, transparent, waterproof and
relatively cheap and affordable by all people.
Plastics that are widely used today are synthetic
polymers made from chemicals that cannot be
decomposed by microorganisms (non-
biodegradable), and use non-renewable
resources, for example from petroleum raw
materials whose existence is running low. .
Based on this, an alternative is needed to solve
this problem by developing biodegradable
plastic materials. Biodegradable plastics are
plastics that can be used for packaging
foodstuffs like conventional plastics that we
have been using, but biodegradable plastics will
break down by microorganism activity to the
end result in the form of water and carbon
dioxide gas after being discharged into the
environment.
Biodegradable plastic can be made from
organic materials that contain cellulose,
callogen, casein starch, protein, or lipids. One
of the plants that can be used as a basic material
in making biodegradable plastics is starch from
Uwi tubers (Dioscorea alata). Uwi tubers
(Dioscorea alata) has not been used maximally
by the community, therefore it would be very
beneficial if it can change the tubers of Uwi into
a product that has a value, one of them as a raw
material for making biodegradable plastics
because it has quite a lot of starch content,
which is around 75.6 - 84.3% (Hapsari, 2014).
Biodegradable plastic made from starch has low
mechanical strength so additional substances
are needed to correct this. Plasticizer is an
additional material added to natural polymers as
plasticizers, because a mixture of pure natural
polymers will produce brittle and brittle
properties that will increase flexibility and
prevent polymers from cracking (Hikmah,
2015).
Journal of Environmental Engineering & Sustainable Technology (JEEST) P-ISSN:2356-3109 Vol. 06 No. 02, November 2019, Pages 57-65
58
The purpose of this research is to study
the process of making biodegradable plastics
from Uwi (Dioscorea alata) by adding CMC and
sorbitol plasticizers and to determine the effect
of adding CMC and sorbitol plasticizers to the
physicochemical properties of plastic from Uwi
tubers (Dioscorea alata) including solubility,
thickness, tensile strength, elongation, modulus
young, compressive strength, biodegradability,
and surface morphology of functional groups.
2. RESEARCH AND METHODS
2.1. Tools and materials
The tools used were a hot plate stirrer,
oven, blender, sieve 100 mesh, analytical
scales, measuring cups, stirrers, stopwatch,
glass plates, buckets, trays, bowls, knives,
basins, ruler. Materials used were Uwi tubers
(Dioscorea alata), CMC (Carboymethyl
Cellulose), sorbitol, distilled, Acetone.
Figure 1. Making Biodegradable Plastic from Uwi
Tuber
2.2. Procedure Data Analysis
2.2.1. Water content
Calculation of water content begins by
weighing the mass of the sample with a sample
size of 2 x 2 cm. Then dry it in the oven at 105⁰C
for 4 hours. Then cool in a desiccator for 15
minutes then weight. Then it is reheated in the
oven for 30 minutes. Then cooled in a
desiccator then weighed.
2.2.2. Solubility
The solubility calculation begins by
weighing the initial mass of biodegradable
plastic first. Then immerse the biodegradable
plastic into aquades for 24 hours while
periodically stirring. After 24 hours,
biodegradable plastic is taken and dried at room
temperature. Then the mass of biodegradable
plastic is weighed again after soaking.
Solubility calculations using the formula
(Andriyani, 2018) :
Solubility (%) =B1 − B2
B1 x 100% ............. (1)
Where : B1: Mass sample before immersion (g) B2: sample mass after immersion (g)
2.2.3. Thickness
Thickness measurements are measured
using a coating thickness gauge. biodegradable
plastic measurements are carried out at three
different points, that is the sides and middle of
biodegradable plastic. Thickness values are
obtained from the average measurement results.
This test was carried out three times (triplo).
The value of biodegradable plastic thickness is
obtained using the following formula: Average thickness =
(point 1 + point 2 + point 3 )
3
2.2.4. Strength test
Biodegradable plastic tensile strength test
is performed using a tension testing tool.
Samples were cut with a size of 3 x 7 cm with a
thickness of ≤ 7 mm, then clamped 1.5 cm in
both sides. Extension indicator (extensomer)
installed. Transverse strain gauges installed.
Load and voltage measurements were taken.
The speed of testing is set according to the rate
required. The stress-load curve is recorded.
Also noted are the voltage and load values as
Start
Preparation of material, and equipment
Oven drying at 60ᵒC for 4 hours
Stirr using magnetic stirred for 25 minutes
Add CMC and sorbitol during mixing
Gelatinize at 80ᵒC for 25 minutes
Let stand 15 minutes to get air bubbles out
Platting on a glass plate with a size 20 x 20 cm
5 gram uwi flour + 5 ml distilled water and add 15
ml acetone
Plastic Biodegradable
Finish
Indriani, Sumarlan, Munawaroh, Physicochemical Characterization of Biodegradable Plastic …
P-ISSN:2356-3109 E-ISSN 2356-3117 59
well as the voltage and load values at the time
of breaking up (Jabbar, 2017)
2.2.5. Elongation
Biodegradable plastic tensile strength test
is performed using a tension testing tool.
Samples were cut with a size of 3 x 7 cm with a
thickness of ≤ 7 mm, then clamped 1.5 cm in
both sides. Extension indicator (extensomer)
installed. Transverse strain gauges installed.
Load and voltage measurements were taken.
The speed of testing is set according to the rate
required. The stress-load curve is recorded.
Also noted are the voltage and load values as
well as the voltage and load values at the time
of breaking up (Jabbar, 2017).
2.2.6. Young's Modulus
Biodegradable plastic tensile strength test
is performed using a tension testing tool.
Samples were cut with a size of 3 x 7 cm with a
thickness of ≤ 7 mm, then clamped 1.5 cm in
both sides. Load and voltage measurements
were taken. The speed of testing is set according
to the rate required. The stress-load curve is
recorded. Also noted are the voltage and load
values as well as the voltage and load values at
the time of breaking up (Jabbar, 2017).
2.2.7. Biodegradability
Calculation of biodegradability begins
with weighing the initial mass of biodegradable
plastic first. Then immerse biodegradable
plastic into distilled water for 24 hours while
stirring periodically. After 24 hours,
biodegradable plastic is taken and dried at room
temperature. Then the mass of biodegradable
plastic is weighed again after soaking
(Andriyani, 2018)
3. RESULTS AND DISCUSSION
3.1. Biodegradable Plastics from Uwi Tuber
Overall, the plastic that is produced from
a variety of treatments is clear in color, the
surface is a bit rough, transparent, sticky and
easy to stick when in contact with other objects.
Figure 1, Biodegradable Plastics
This moist and sticky nature is caused by
the nature of CMC which is easy to absorb the
surrounding steam.
3.2. Water Content
Moisture test is performed to determine the
water content of biodegradable plastic. The
results of water content analysis showed that
the treatment of adding 0.4 grams of CMC and
4 ml of sorbitol had the largest water content of
16.97% and the treatment of adding 0 grams of
CMC and 2 ml of sorbitol had the lowest water
content of 12.50%. Average water content of
14.54%.
Figure 2, Graph of Biodegradable Plastic Water
Content (%) Due to the addition of CMC (g) and sorbitol (ml)
The process of making biodegradable
plastic when drying uses a temperature of 60 °
C for 4 hours that will evaporate free water that
is not bound by sorbitol and CMC, but not all
free water can be evaporated. Adding a low
concentration of sorbitol and CMC results in a
low amount of bound water. Meanwhile, the
addition of high concentrations of sorbitol and
CMC can increase the ability to bind water and
increase the total amount of water so that the
water content in the biodegradable plastic
formed has a high water content value.
According to Rahayu (2016), the more CMC
and sorbitol added the higher the water content
value.
3.3. Solubility
The solubility obtained from the
measurement results of biodegradable plastic
samples ranged from 23.87% to 66.01%. The
average solubility value is 51.71%. Based on
ANOVA analysis showed the influence of the
addition of CMC and sorbitol gave significant
results at α <0.05 on the resulting solubility. The
interaction of the combination of the two factors
0
5
10
15
20
0 0.2 0.3 0.4W
ater
Co
nte
nt
(%)
CMC Concentration (gram)
Sorbitol 2 ml
Sorbitol 3 ml
Sorbitol 4 ml
Sorbitol 5 ml
Journal of Environmental Engineering & Sustainable Technology (JEEST) P-ISSN:2356-3109 Vol. 06 No. 02, November 2019, Pages 57-65
60
also had a significant effect on α> 0.05 so that a
further DMRT (Duncan Multiple Range Test)
test was performed. Based on the DMRT test
that has been obtained, the results for the CMC
factor show that the 0.30 and 0.40 gram
treatments have a more significant effect on the
elongation value of biodegradable plastics
compared to the 0 and 0.20 gram treatments that
are in the second subset. However, the inter
treatment did not have a significantly different
effect. As for the addition factor of sobitol
treatment 2, 3 and 5 mL gives a more significant
effect compared to 5 mL treatment. However,
between treatments did not have a significantly
different effect,
Figure 3. Graph of Biodegradable Plastic Solubility
(%) Due to the addition of CMC (g) and sorbitol
(ml)
Based on the graph above shows that the
greatest biodegradable plastic solubility is at
0.40 gram CMC treatment and 5 ml sorbitol,
with an average of 51.71%, while the smallest
biodegradable plastic solubility is at 0 gram
CMC treatment and 2 ml sorbitol treatment is
26, 72% and the smallest biodegradable plastic
solubility was at CMC 0.40 gram and sorbitol 5
ml at 63.31%. This shows that the solubility
value increases with the addition of CMC and
sorbitol concentrations. In this study, the graph
is not fluctuating. This is due to the non-uniform
thickness of the plastic. The thickness of the
plastic affects its solubility, meaning that the
thicker the plastic, the lower the solubility due
to the compactness of the film as a result of
increasing hydrogen bonds as the thickness of
the plastic increases. Increased hydrogen bonds
cause the molecular structure of starch to bond
together to form a compact network, thereby
reducing the solubility of plastic. CMC is a type
of stabilizer of carbohydrates that can form
colloids in water. The colloidal nature of this
substance as a stabilizer or can stabilize the
suspension. The more addition of CMC causes
more water to be absorbed, which is caused by
CMC being hygroscopic (Nasution et al, 2015).
Addition of sorbitol to the film increases water
solubility. Type and concentration give effect to
the solubility of starch-based films. The more
plasticizer additions will increase the solubility
(Nurhayati et al. 2012). Based on these results
prove that the addition of CMC and sorbitol
more and more will increase water solubility.
3.4. Thickness
The tensile strength obtained from the
measurement results of biodegradable plastic
samples ranged from 14.25 MPa to 76.65 MPa.
Based on the analysis showed the influence of
the addition of CMC and the addition of sorbitol
gave significant results at α <0.05 to the
resulting tensile strength value. The interaction
of the combination of the two factors did not
have a significant effect on α> 0.05, so a further
DMRT (Duncan Multiple Range Test) test was
performed. Based on the DMRT test results
obtained for the CMC factor that the treatment
of 0, 0.20 and 0.40 grams have a more
significant influence on the tensile strength
value of biodegradable plastics in subsets 2 and
3 compared to 0.30 gram treatments that are in
subset 1.
Figure 4. Graph of Thickness Due to Addition of
CMC and Sorbitol
Based on the graph above shows that the
largest biodegradable plastic thickness is at 0.30
gram CMC treatment and 4 ml sorbitol, with an
average of 97.12 µm, while the smallest
biodegradable plastic thickness is at 0.30 gram
CMC treatment and 3 ml sorbitol treatment at
41.07 µm. That the addition of CMC and
sorbitol tends to produce different thickness
thicknesses. The average thickness of
biodegradable plastic is 71.36 µm. This is due
to the influence of printing which is possible for
0
20
40
60
80
0.00 0.20 0.30 0.40
Solu
bili
ty (
%)
CMC Conc. (gram)
Sorbitol 2 ml
Sorbitol 3 ml
Sorbitol 4 ml
Sorbitol 5 ml
0
50
100
150
0.00
0.20
0.30
0.40
Thic
knes
s (µ
m)
CMC Concentration (gram)
sorbitol 2 ml
sorbitol 3ml
sorbitol 4ml
sorbitol 5ml
Indriani, Sumarlan, Munawaroh, Physicochemical Characterization of Biodegradable Plastic …
P-ISSN:2356-3109 E-ISSN 2356-3117 61
differences on each side of the glass plate
because the printing process is done manually.
The difference in magnitude of the resulting
thickness is due to the process of making the
solution.
3.5. Tensile Strength
The tensile strength obtained from the measurement results of biodegradable plastic samples ranged from 14.25 MPa to 76.65 MPa. Based on the analysis showed the influence of the addition of CMC and the addition of sorbitol gave significant results at α <0.05 to the resulting tensile strength value. The interaction of the combination of the two factors did not have a significant effect on α> 0.05, so a further DMRT (Duncan Multiple Range Test) test was performed. Based on the DMRT test results obtained for the CMC factor that the treatment of 0, 0.20 and 0.40 grams have a more significant influence on the tensile strength value of biodegradable plastics in subsets 2 and 3 compared to 0.30 gram treatments that are in subset 1. However, between treatments did not have a significantly different effect. Whereas the addition factor of sobitol treatment 2 and 3 mL gives a more significant effect compared to treatments 4 and 5 mL. However, between treatments did not have a significantly different effect.
Figure 5. Graph of Strength Test Biodegradable
Plastics (MPa) Due to the addition of CMC (g) and
sorbitol (ml)
Based on the graph shows that the
greatest tensile strength of biodegradable
plastic is at CMC treatment of 0 gram and
sorbitol 2 ml, with an average of 76.66 MPa,
while the smallest tensile strength of
biodegradable plastic is at CMC treatment of
0.40 gram and sorbitol of 5 ml that is by an
average of 14.25 MPa. This shows that the
tensile strength value decreases with the
addition of CMC and sorbitol concentrations.
On the addition of CMC decreased showed that
the molecular structure is amorphous.
According to Hasanah et.al (2016), in the
structure of amorphous molecules, chains are
branched but not tightly arranged so that the
distance between molecules becomes farther
and the strength of molecular bonds becomes
weak. The weak strength of the molecular
bonds causes the lower force required to break
the biodegradable plastic. According to
Purwanti (2010), with the addition of sorbitol as
a plasticizer, the plasticizer molecules in the
solution are located between the biopolymer
bonding chains and can interact by forming
hydrogen bonds in the polymeric bonding
chains causing a reduction in less attraction with
the addition of sorbitol.
3.6. Elongation
Extensions obtained from the measurement results of each biodegradable plastic sample ranged from 10% - 38.33%, while the percentage of overall lengthening of biodegradable plastics was an average of 23.85%. Based on ANOVA analysis showed the influence of the addition of CMC and sorbitol gave significant results at α <0.05 on the resulting elongation. The interaction of the combination of the two factors also had a significant effect on α <0.05 so that further tests were carried out by DMRT (Duncan Multiple Range Test). Based on the DMRT test results obtained for the CMC factor that the treatment of 0.20, 0.30 and 0.40 grams give a more significant effect on the elongation value of biodegradable plastics while the treatment of 0 grams does not give a more significant effect on the elongation value is in the second subset. However, the inter treatment did not have a significantly different effect. As for the Sobitol factor treatment 2 and 3 mL gave a more significant effect compared to treatment 5 and 4 mL. However, between treatments did not have a significantly different effect.
Figure 6. Graph of Elongation (%) As a result of
addition of Biodegradable Plastic result CMC (g)
and sorbitol (ml)
0
20
40
60
80
100
0.000.200.300.40
Ten
sile
Str
engh
(M
Pa)
CMC Concentration (gram)
Sorbitol 2 ml
Sorbitol 3 ml
Sorbitol 4 ml
Sorbitol 5 ml
0
20
40
60
0 0.2 0.3 0.4
Elo
nga
tio
n (
%)
CMC Concentration (gram)
sorbitol 2ml
sorbitol 3ml
sorbitol 4ml
sorbitol 5ml
Journal of Environmental Engineering & Sustainable Technology (JEEST) P-ISSN:2356-3109 Vol. 06 No. 02, November 2019, Pages 57-65
62
Based on the graph shows that the largest
biodegradable plastic elongation was at CMC
0.20 gram and sorbitol 5 ml with an average of
39.44%, while the smallest biodegradable
plastic elongation was at 0 gram CMC treatment
and 2 ml sorbitol at 13.89%. This shows the
value of elongation has increased along with the
addition of CMC and sorbitol concentrations.
CMC has high gel strength. The use of CMC in
larger amounts causes better water-binding
ability thus providing a gel matrix which can
increase percent elongation.
3.7. Young's Modulus
Young's modulus is obtained by comparing stress and strain. In biodegradable plastic with the addition of CMC, the amount of modulus of young is varied. Young modulus calculation results obtained the largest Young modulus value is 5.56 MPa and the smallest Young modulus value is 0.553 MPa. Based on ANOVA analysis showed the influence of the addition of CMC and sorbitol gave significant results at α <0.05 on Young's modulus produced. The interaction of the combination of the two factors also had a significant effect on α <0.05 so that further tests were carried out by DMRT (Duncan Multiple Range Test). Based on DMRT test results obtained for the CMC factor that the treatment 0, 0.20 and 0.40 grams give a more significant effect on the modulus of Young biodegradable plastic while the treatment of 0.30 grams does not give a more significant effect on the modulus value Young Significant influences are indicated by those in the second subset. However, the inter treatments did not have a significantly different effect because α> 0.05. As for the sorbitol factor treatment 2 3, and 4 mL gives a more significant effect compared to the 5 mL treatment. However, between treatments did not have a significantly different effect.
Figure 7. Graph of Young's Modulus
Biodegradable Plastic Due to Addition of CMC
Based on the graph shows that Young's
modulus of biodegradable plastic is the largest
average in the treatment of 0 gram CMC and
sorbitol 2 ml, with an average of 5.52 MPa,
while Young's modest biodegradable plastic is
the smallest average in CMC treatment of 0.30
gram and 4 ml sorbitol, with an average of 0.62
MPa. Young's modulus value is directly
proportional to the value of tensile strength.
3.8. Compressive Strength
The compressive strength obtained from
the measurement results of biodegradable
plastic samples ranged from 0.06 kgf to 0.47
kgf. The average compressive strength is 0, 27
kgf. Based on ANOVA analysis, the effect of
adding CMC and sorbitol gave significant
results at α <0.05 on the compressive strength
produced. The interaction of the combination of
the two factors also had a significant effect on α
<0.05 so that further tests were carried out by
DMRT (Duncan Multiple Range Test). Based
on the DMRT test that has been obtained, the
results for the CMC addition factor show that 0
and 0.20 gram treatments have a more
significant influence on the compressive
strength value of biodegradable plastics
compared to 0.30 and 0.40 gram treatments that
are in the second subset. However, the inter
treatment did not have a significantly different
effect. Whereas the addition factor of sorbitol
treatment 3 and 5 mL gives a more significant
effect compared to treatment 2 and 4 mL.
However, between treatments gave
significantly different effects on the treatment
of sorbitol 2 and 4 ml α = 0.05.
Figure 8. Graph Biodegradable Plastic
Compressive Strength (kgf) Due to the addition of
CMC (g) and sorbitol (ml)
0.00
2.00
4.00
6.00
0 0.2 0.3 0.4
You
ng'
s M
od
ulu
s (M
Pa)
CMC Concentration (gram)
Sorbitol 2 ml
Sorbitol 3 ml
Sorbitol 4 ml
Sorbitol 5 ml
0
0.1
0.2
0.3
0.4
0.5
0 0.2 0.3 0.4Co
mp
ress
ive
Stre
ngh
(K
gf)
CMC Concentration (gram)
sorbitol 2ml
sorbitol 3ml
sorbitol 4 ml
sorbitol 5 ml
Indriani, Sumarlan, Munawaroh, Physicochemical Characterization of Biodegradable Plastic …
P-ISSN:2356-3109 E-ISSN 2356-3117 63
Based on the graph shows that the
greatest compressive strength of biodegradable
plastic is at CMC treatment of 0 grams and
sorbitol 2 ml, with an average of 0.45 kgf, while
the smallest compressive strength of
biodegradable plastic is at CMC treatment of
0.40 grams and sorbitol 5 ml, namely with an
average of 0.15 kgf. This shows the value of
compressive strength decreased with increasing
concentrations of CMC and sorbitol. This is due
to CMC in the form of a small size molecule
that is between the starch chains, such as the
position of sorbitol. The effect of the surfactant
position can result in a decrease in
intermolecular interactions between starch
molecules, increase free space between the
starch chains, and increase polymer mobility.
As a result of these effects, the integrity of the
matrix structure of the film decreases and the
impact on the compressive strength of the edible
film decreases. Brandelero et al. (2010) added
that edible films containing surfactants had
lower compressive strength values than without
surfactants. The decrease in compressive
strength can be related to the increase of free
space between adjacent starch chains. This is in
accordance with Santoso (2012), that the more
addition of CMC in plastics increases the
compressive strength.
3.9. Biodegradability
Biodegradation testing is carried out using Effective Microorganism 4 (EM4). The results showed the greatest biodegradable value at 0.30 gram CMC and 4ml Sorbitol that is equal to 94.41%. While the smallest biodegradable value at the addition of 0 grams and 2ml sorbitol is equal to 29.13%. The average value of biodegradable plastic is 23.87%. Based on ANOVA analysis showed the influence of the addition of CMC and both factors gave significant results at α <0.05 on the biodegradable produced. The addition of sorbitol did not have a significant effect on α> 0.05 so that further tests were carried out DMRT (Duncan Multiple Range Test). Based on the DMRT test that has been done, it is obtained the results for the addition of CMC factors that the treatment of 0.30 and 0.40 grams gives a more significant effect on the biodegradable value compared to treatments 0 and 0.20 grams which are in the second subset. However, the inter treatment did not have a significantly different effect. Whereas the addition factor of sobitol treatment 2 and 4 mL
gives a more significant effect than treatment 3 and 5 mL. However, between treatments gave significantly different effects on the treatment of sorbitol 2 and 4 ml α = 0.05.
Figure 9. Graph of Biodegradable (%) Due to the
addition of CMC (g) and sorbitol (ml).
Based on the picture shows the greatest
biodegradable value at 0.30 gram CMC and 4ml
Sorbitol that is equal to 82.81%. While the
smallest biodegradable value at the addition of
0 grams and 2ml sorbitol is equal to 29.13%.
The average value of biodegradable plastic is
58.9447%. The rate of biodegradation of
biodegradable plastics increases with the
addition of CMC which can be seen in Fig.
According to Hasanah (2016), the addition of
CMC actually increases the hydrophilic nature
of the plastic produced. As a result, plastic has
a high level of humidity. A good biodegradable
plastic that has strong mechanical properties,
but also environmentally friendly (high
biodegradability).
3.9.1. SEM (Scanning Electron Microscopy)
Tests carried out on biodegradable
plastics that have the highest and lowest tensile
strength values. The samples tested were at 0
gram CMC mass and 2ml Sorbitol which were
the best treatment and 0.40 gram CMC mass
and 5ml sorbitol using 500x magnification.
Picture 1, Biodegradable Plastic structure with the
addition of CMC 0 g and Sorbitol 2 ml (a).
Biodegradable Plastic structure with the addition of
0.40 grams of CMC and sorbitol 5 ml
a b
0%
20%
40%
60%
80%
100%
0 0.2 0.3 0.4Bio
deg
rad
able
(%
)
CMC Concentration (gram)
sorbitol 2ml
sorbitol 3ml
sorbitol 4ml
sorbitol 5ml
Journal of Environmental Engineering & Sustainable Technology (JEEST) P-ISSN:2356-3109 Vol. 06 No. 02, November 2019, Pages 57-65
64
SEM test results show that the microscopic
surface of biodegradable plastic with the
addition of CMC 0 gram and sorbitol 2 ml
surface morphology is smoother, whereas on
biodegradable plastic with the addition of CMC
0.40 gram and sorbitol 5 ml surface morphology
is rougher. This is not in accordance with
Tondang's research (2018), which states that the
surface morphology is more close where the
addition of CMC affects the surface structure of
the film. The higher the concentration of CMC
added by surface morphology, the closer it is
because CMC is often used as an emulsifier to
improve texture appearance. This result is likely
due to an uneven mixing process.
3.9.2. FTIR (Fourier Transform Infrared
Spectroscopy)
Infrared spectroscopic analysis aims to
determine the functional groups of organic and
inorganic compounds. Tests carried out on
biodegradable plastics that have the highest and
lowest tensile strength values. The samples
tested were at 0 gram CMC mass treatment and
2ml Sorbitol which was the best treatment and
0.40 gram CMC mass and 5ml sorbitol
treatment.
Figure 10, The spectrum of biodegradable plastics
with the addition of CMC concentration of 0.40
grams and the addition of 5 ml Sorbitol
Figure 11, The spectrum of biodegradable plastics
with the addition of CMC concentration 0 grams
and the addition of 2 ml Sorbitol
Based on Figures 11 and 12 show that
with the variation of the addition of CMC and
the addition of sorbitol appear several
vibrational peaks. The functional group of CO
alcohol appeared at the peak of 1062.78 cm-1,
CO ether which was at the peak of 1166.93 cm-
1, CO carboxylic acid which was at the peak of
1340.53 cm-1, CO ester which was at the peak
of 1062, 78 cm-1. At a wavelength of 2100-
2260 cm-1 which indicates the functional group
C = C Alkuna which is at the peak of 2146.77
cm-1. At a wavelength of 3200-3600 cm-1,
there is a functional group of hydrogen bonds
with an absorption peak at the number 3342.64.
FTIR test results in the form of functional
groups can be used as an indicator that the
plastic produced can still be degraded. This is in
accordance with the opinion of Setiawan (2014)
that in addition to hydroxide (OH) groups other
functional groups contained in plastics are
carbonyl (CO) groups and ester groups, so that
by having these functional groups plastic films
can be degraded. In the results of the FTIR test
conducted in this study obtained ester
functional groups, the resulting plastic film can
be degraded.
4. CONCLUSIONS
From the research that has been done with
the basic ingredients of starch uwi tuber
(Dioscorea alata) with the addition of CMC and
sorbitol plasticizer, it can be concluded that :
1. In the process of making biodegradable
plastics from Uwi tubers with the addition
and plasticizer of sorbitol as a whole the
plastic is produced from a variety of clear
colored treatments, the surface is slightly
rough, transparent, sticky and easy to stick if
in contact with other objects. The average
thickness of the plastic is 71.36 µm and the
average moisture content is 14.54%.
2. The concentration of the addition of CMC
and sorbitol plasticizer on bidegradable
plastic affects the mechanical properties of
tensile strength, elongation, modulus young
and compressive strength. the best tensile
strength value on the addition of cmc 0 gram
and sorbitol 2 ml is equal to 76.66 MPa, the
best elongation value at the addition of CMC
is 0.20 gram and sorbitol 5 ml is equal to
39.44%, the best young modulus value is at
adding cmc 0 gram and sorbitol 2 ml which
Indriani, Sumarlan, Munawaroh, Physicochemical Characterization of Biodegradable Plastic …
P-ISSN:2356-3109 E-ISSN 2356-3117 65
is 5.52 MPa and the lower the compressive
strength value is 0.150 kg / cm2.
3. Concentration of 0.40 gram CMC addition
and sorbitol 5 ml plasticizer on
biodegradable plastic affect biodegradability
of biodegradable plastic that is degraded
plastic at 7 days.
5. REFERENCES
Anggraini, Meilan. 2016. Pengaruh Konsentrasi
Carboxy Methyl Cellulose (Cmc) dan
Lama Penyimpanan Pada Suhu Dingin
Terhadap Stabilitas Dan Karakteristik
Minuman Probiotik Sari Buah Nanas.
Bandar Lampung: Universitas
Lampung
Hapsari, Ratri Tri. 2014. Prospek Uwi Sebagai
Pangan Fungsional dan Bahan
Diversifikasi Pangan. Buletin Palawija
No. 27
Hasanah, Y. R., Umi.U.K., Endang.W.,
Haryanto. 2016. Pengaruh Penambahan
Cmc (Carboxy Methyl Cellulose)
Terhadap Tingkat Degradibilitas Dan
Struktur Permukaan Plastik Ramah
Lingkungan. Simposium Nasional
Teknologi Terapan. Purwokerto:
Universitas Muhammadiyah
Purwokerto
Hikmah, Nurul. 2015. Pemanfaatan Limbah
Kulit Pisang Ambon (Musa
Paradisiacal) Dalam Pembuatan Plastik
Biodegradable Dengan Plasticizer
Gliserin. Palembang: Politeknik Negeri
Sriwijaya
Jabbar, Uhsnul Fatimah. 2010. Pengaruh
Penambahan Kitosan Terhadap
Karakteristik Plastik biodegradable
Dari Pati Kulit Kentang (Solanum
Tuberosum. L). Makassar: UIN
Alauddin Makassar
Nurhayati, S. W., Dwi K., Yuni T.N. 2012.
Pengaruh Penambahan Sorbitol Dan
Kalsium Karbonat Terhadap
Karakteristik Dan Sifat Biodegradasi
Film Dari Pati Kulit Pisang. Molekul.
Vol:7(1). Hal: 75
Purwanti, Ani. 2010. Analisis Kuat Tarik dan
Elongasi Plastik Kitosan Terplastisasi
Sorbitol. Jurnal Teknologi. Vol: 3(2).
Hal: 102
Rahayu, Astria Pengesti. 2016. Kajian
Karakteristik Edible Film Pati Hanjeli
(Coix Lacyma–Jobi L.) Dengan
Pengaruh Konsentrasi Pemlastis
Sorbitol Dan Konsentrasi Penstabil
Cmc. Bandung: Universitas Pasundan
Rifaldi, Anugerah, Irdoni Hs, Bahruddin. 2017.
Sifat dan Morfologi Plastik
biodegradable Berbasis Pati Sagu
dengan Penambahan Filler Clay dan
Plasticizer Gliserol. Jom FTEKNIK.
Vol:4(1). Hal: 3
Santoso, B., Filli.P., Basuni.H., Rindit.P., 2012.
Perbaikan Sifat Mekanik Dan Laju
Transmisi Uap Air Edible Film Dari
Pati Ganyong Termodifikasi Dengan
Menggunakan Lilin Lebah dan
Surfaktan. Agritech. Vol: 32(1). Hal:
11-12
Setiawan, H., Musthofa L, dan Masruroh. 2014.
Optimasi Plastik Biodegradable
Berbahan Jelarut (Marantha
arundinacea L) dengan Variasi LLDPE
untuk Meningkatkan Karakteristik
Mekanik. Jurnal Keteknikan Pertanian
Tropis dan Biosistem Vol. 2(2). Hal:
128