Study On Preparation And Property Of Biodegradable PBS/Starch Composites

Plastic has been widely used in agricultural production and daily life, and become the material of the four pillars of the world, because of its unique variety of excellent performance. But the Government as well as the social had been afraid of white pollution caused by plastic since the20th century, and therefore people urgently demand materials which is non-hazardous,not only to our body but also to the environment, while it retains some performance of the plastic. Biodegradable plastics will come into being, therefore has a broad application prospects, and more and more attention has been paid. Polybutylene succinate ester (PBS) is more commonly used in the biodegradable plastics, as compared with other biodegradable plastics, due to it’s excellent mechanical properties, good heat resistance and processing properties (the best among many biodegradable materials). What’s moreover, PBS classes polyester is very stable in normal storage and use of the process, which is degrade only contacting microorganisms. PBS/starch composites gives the rapidly degradable and greatly reduce the cost on the basis of retaining PBS certain good performance.In this paper, we used polybutylene succinate(PBS) as a matrix resins, and starch as filler to modify PBS.Starch granules as a filler was added to the PBS, and played a role similar to the inorganic filler reinforced. The polybutylene succinate/starch composites were prepared by melt blending based on the surface treatment of starch in this subject, and the mechanical properties of the composite material, a melt index, thermal stability, waterproof performance, and degradation properties was studied. As well as, we discussed the dispersion of starch filler in the matrix resin PBS and the crystallization and melting with a scanning electron microscope (SEM) and differential scanning calorimetry(DSC). The results are as follows:(1)the influence of starch content on the mechanical properties of the blend system:we found that the tensile strength, bending strength of the composite material is reduced, and little change in bending strength, modulus of elasticity is improved by measuring the mechanical properties of the composite material with different starch content. The complexes is relatively good when starch is added in an amount of25%(based on the matrix resin),taking the production cost of PBS and the impact on the material properties adding starch into account,in which the tensile strength and notched impact strength retained72%and77%,and tensile modulus and flexural modulus were increased by50%and38.3%.(2) The types of coupling agent and it’s amount will also affect the composite performance. The coupling agent can improve the compatibility between polybutylene succinate and starch in a certain extent. The experimental results showed that:choosing L-1H aluminum coupling agent to improve the compatibility of the composite materials will be better;When the addition of coupling agent was1%(based on filler),the cost-effective is better;(3) A plasticizer added and the amount of plasticizer will also has an effect on the material properties. Various types of plasticizer have an different influence: when choosing glycerol and urea as plasticizer at the same time, mechanical properties and melt flow and thermal stability are better relative to other single or compound plasticizers in the text;When the plasticizer was10%,the mechanical properties is better;(4) The various diluents to dilute coupling agents and plasticizers and the order of feeding would affect material properties too. We found that the composite performance used anhydrous alcohol as diluents was better; When we first added starch plastified and then mixed with PBS and coupling, the performance was better.(6)We also measured the biodegradability and the water resistance of the composites in this article. Biodegradability of the material is improved when adding starch comparing with pure PBS, and the degradation rate was increased by approximately908%; the water resistance was reduced compared with pure PBS;(7)SEM and DSC analysis showed that:the addition of starch had an impact on the morphology and structure of the material. The SEM figure shows:we can see that the starch granules clearly from scanning electron micrograph of the composite material, compared with composites without additives, the starch granules are better dispersed in the matrix resin PBS in the composites adding additives; the DSC figure shows that starch did not change the crystal type of PBS, but reduce the melting and crystallization starting temperature in some extent.