癸二酸二苯甲酰肼对PLA等温结晶行为及拉伸性影响

采用熔融共混法制备聚乳酸/癸二酸二苯甲酰肼(PLA/SBH)共混物。通过差示扫描量热(DSC)分析研究成核剂SBH添加量以及等温温度对PLA熔体等温结晶行为的影响。由结晶动力学分析可知,随着SBH添加量增大,PLA半结晶时间大幅缩短,结晶速率显著加快。加入SBH后,Avrami指数在2.51~3.14之间,PLA熔体结晶以异相成核为主,晶体生长为三维生长。对于PLA急冷模压样条,结晶度仅为2.9%。而加入1.0份SBH后,PLA熔体在134℃下经过3 min等温结晶处理后,所得PLA/SBH(100/1.0)模压样条结晶度达到42.0%。相对于急冷PLA样条,经过热处理的PLA/SBH(100/1.0)样条的维卡软化点由64.3℃大幅提升至160.6℃,而拉伸强度也有所增大。

Influence of SBH on Isothermal Crystallization Behavior and Tensile Performance of PLA

Polylactide/sebacate benzohydydrazide (PLA/SBH) were prepared by melt blending method. Effect of SBH loading,as well as temperature on isothermal crystallization behavior of PLA melt was researched by using differential scanning calorimetry (DSC). From crystallization kinetic analysis,it can be pointed to the fact that crystallization half time of PLA significantly be reduced and its isothermal crystallization rates largely accelerated with increasing of SBH loadings. With the introduction of SBH,Avrami constant is in the range of 2.51 and 3.14. As a result,it is confirmed that the nucleation type of PLA/SBH blend should be heterogeneous nucleating and its growth mode should be 3D growth. For quenched PLA specimen,its crystallinity is only 2.9%. However,while PLA/SBH (100/1.0) melt has been isothermally crystallized at 134℃ for 3 min,the crystallinity of the obtained specimen reach to 42.0%. As a result,vicat softening point of the crystallized PLA/SBH specimen increase from 64.3℃ for the quenched PLA specimen to 160.6℃ significantly. Moreover,PLA/SBH specimen also show a slight increase in tensile strength.