Study On Blending Of Polylactic Acid With Modified Starch And Polyhydroxy Fatty Acid Ester

With the diminish of oil resources and the aggravation of white pollution, people began to pay attention to the protection of the environment and the development of renewable resources, so the biodegradable material begins concern. Due to biodegradable polymer has good degradation, non-toxic, renewable sources and biocompatibility are widely used in medical, agricultural, food packaging and cosmetics industries, as the most likely to replace traditional plastic materials.In such materials, duing to the good biocompatibility and biodegradability of the polylactic acid(PLA), which has been studied extensively. However, PLA also has many shortcomings, PLA as a semi-crystalline materials, the molecule contains a large number of hydrogen bonds, illiduid, broad molecular weight and so on, leading to insufficient properties of the final spinning fiber obtained. Therefore, in order to improve the performance of PLA, reduce the crystallinity, increase their mobility and properties of PLA fibers.In this work, we use melt blending extrusion method to prepare PLA modified materials which was blend with starch and polyhydroxyalkanoates(PHA). Then the modified materials were used to obtain the fibers by melt spinning. The melt index, differential scanning calorimetry(DSC), tensile properties, thermal properties and mechanical properties. Determine the optimum blending extrusion and melt spinning process parameters. After analysis of that, modified starch was added, along with the increase of PEG content, the fluidity of the material and the elongation at break are increased, the breaking strength is decreased, plays a good role in the increase of plastic. When the content of PEG is 6 percent, the mechanical properties of the fiber are the best. Add the PEG into PLA/PHA blends, with the increase of PHA content, the fluidity of the material and the elongation at break are increased, the breaking strength is decreased. When the PHA content is more than 8 percent, the mechanical properties of the fiber are greatly reduced. The mechanical properties of the blend fibers were the best when the content of PHA was 8 percent.