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The motivation of this work is to lessen the dependence on non-degradable plastic
packaging which can lead to waste disposal problems. In this paper, the alternative biodegradable
material developed by using local available sago starch in the present of biodegradable glycerol as
plasticizer, as well as a set of composition added with citric acid as co-plasticizer is reported. Starch
was added with 15-30 w/w% of glycerol to prepare workable bioplastics. The samples were
characterized by Thermal Gravimetric Analysis (TGA), Fourier Transform Infrared (FTIR) and
tested for mechanical properties. The results reveale that, the tensile strength of the bioplastic is
increasing with the increasing of glycerol until the optimum amount of 30 w/w%. The similar trend
is also observed upon the addition of the citric acid. The decrease of the strength after the optimum
point, however is obvious in the specimens with the addition of citric acid which is about 50%
lower than the specimen without citric acid.
It is undeniable, although conventional plastic is good, but it still has some limitations. As a fact,
many researchers emphasized that plastic waste leads to environmental problems. According to
Santos [1], conventional plastic offer bad consequences for the environment due to common
polyolefins which have very poor degradation rate. This fact is supported by Fischer [2], who
claimed that high cost is needed to store the non-degradable plastic while burning it will produce
carbon dioxide (CO
2
) which leads to green house effect. For the stated reasons, it can be concluded
that the usage of conventional thermoplastic make the environmental problem become crucial [1-2].
Thermoplastic starch has been introduced as an attempt to overcome these drawbacks.
Thermoplastic starch (TPS) is a homogenous thermoplastic substance made from native starch.
After undergoes several processes, thermoplastic starch may transform from semi-crystalline into
amorphous polymeric material. It should be noted that, thermoplastic starch is practical to be used
due to it has starch content more than 70% and with the use of specific plasticizing solvents,
materials with good properties and biodegradability can be produced.
Sago starch is a true wonder of nature and known as the most important raw material due to its
low cost, availability as a renewable resource, biodegradable and the harmless degradation products
[3]. Sago starch can be processed into thermoplastic starch under the action of temperature and
shearing action. Plasticizer need to be used while processing, because of the low decomposition
temperature of the granular starch [4].
This work is undertaken to explore the potential of sago starch as natural sources for the
production of biodegradable thermoplastic. The objectives of this study are to optimize the process
condition in order to produce high performance materials and to study the effect of co-plasticizer on
the mechanical and thermal properties of the thermoplastic starch. Further, tensile fracture specimen
was viewed under scanning electron microscope for morphological analysis.
Key Engineering Materials Vols. 471-472 (2011) pp 397-402
© (2011) Trans Tech Publications, Switzerland
doi:10.4028/www.scientific.net/KEM.471-472.397
All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of TTP,
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