P(3,HB-co-4,HB)/PLA共混物的扩链改性研究

以异佛尔酮二异氰酸酯(IPDI)和亚磷酸三苯酯(TPP)为扩链剂,对聚(3–羟基丁酸酯–co–4–羟基丁酸酯)/聚乳酸P(3,HB-co-4,HB)/(PLA)]共混物进行扩链改性.采用毛细管流变仪、电子万能试验机、差示扫描量热仪和扫描电子显微镜等研究两种扩链剂及用量对扩链前后共混物的流变性能、力学性能、结晶性能及断面形态的影响.结果表明:两种扩链剂均显著提高了共混物的熔体剪切黏度和两组分间的相容性,IPDI和TPP添加量分别为1.5份和1.0份时,改性效果最明显,共混物断裂伸长率及缺口冲击强度分别提高了34.5%、69.6%和89.6%、81.0%;IPDI扩链体系的拉伸强度提高8.3%,而TPP扩链体系的拉伸强度略有下降,表明IPDI扩链效果优于TPP.

Studies on Chain Extension Modification of P(3,HB-co-4,HB)/PLA Blends

IPDI and TPP were selected as chain extenders to prepare modified poly(3-hydroxybutyrate-co-4-hydroxybutyrate) P(3,HB-co-4,HB)]/polylactic acid(PLA)blends.Capillary rheometer,electronic universal testing machine,differential scanning calorimeter and scanning electron microscope were used to calculate the dasage of the chain entender and characterize their effects of on the rheological,mechanical and crystal properties,as well as the fracture morphologies of the blends.The results show that the compatibility of the two phases and apparent viscosity of blends are obviously improved by the chain extenders.The optimal effect of modification was obtained at 1.5,phr IPDI and 1.0,phr TPP,at which the breaking elongation and impact strength of the blends are 34.5%/69.6% and 89.6%/81.0% respectively.The tensile strength of the blends is increased by 8.3% with 1.5,phr IPDI,slightly better then with TPP.It means that the effect of the chain extension with IPDI is superior to that with TPP.