热塑性淀粉/PBS共混物的微生物降解性研究

Biodegradation of starch/poly(butylene succinate) blends by the selected cultured fungi

以甘油作为增塑剂,采用玉米淀粉与改性后的聚丁二酸丁二醇酯(PBS)熔融共混制备出淀粉/PBS共混材料。对这种改善了两相相容性的共混材料在特定微生物条件下的降解行为进行了研究。结果显示,共混物降解28天后,含有30%PBS的共混物质量损失达到35%左右,其力学性能只有降解前的20%,甘油含量减小和PBS含量增加均能减缓材料的降解。且随着降解时间的延长,PBS的结晶度和熔点有所提高。

In recent years, much progress has been achieved in the development of biodegradable products using agricultural materials as basis, for the environmental threats restrict the use of non-degradable polymers. In order to obtain a cost-effective biodegradable plastic, a novel environmental-friendly stareh/poly （butylene succinate） （PBS） blends with improved compatibility were successfully prepared using glycerol as plasticizer. In this work, the biodegradation behavior of starch/PBS blends was studied by the selected cultured fungi according to the ISO846-1997. The ultimate biodegradation percentage revealed that the blends showed good biodegradability. Rates of weight loss increased with the decrease of PBS contents or the increase of the molecular weight of PBS,which is ascribed to the fact that the dispersed PBS blocked the fungi to attack starch matrix. Moreover,the presence of plasticizer such as glycerol can further influence the biodegradation percentage. For all samples, the weight loss was accompanied by a rapid deterioration in tensile strength and elongation at break. In addition, biodegradation resulted in an increase of crystallinity and melting point in starch/PBS blends.