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为了探究四臂聚乳酸对线性聚乳酸结晶行为的影响,将四臂聚乳酸与线性聚乳酸的共混物在示差扫描量热仪(DSC)和偏振光显微镜(PLM)热台中加热到熔点附近的不同温度下恒温后分别进行了降温—升温程序,考察了四臂聚乳酸对线性聚乳酸的结晶行为的影响.结果表明,随着四臂聚乳酸含量增加,四臂聚乳酸在共混物形成的晶体中的比例增大且四臂聚乳酸有促进共混物晶体完善的作用,导致了熔融过程中熔点的上升.进一步研究证明,在共混物中完全熔融的四臂聚乳酸的支化结构能够促进结晶成核点的形成,从而促进四臂聚乳酸/线性聚乳酸共混物的结晶;而部分熔融的四臂聚乳酸能大幅促进共混物的结晶能力,这是未完全熔融的晶体的成核作用所导致的.
In order to investigate the effect of four-arm polylactic acid on the crystallization behavior of linear polylactic acid, a blend of four-arm polylactic acid and linear polylactic acid was heated in the vicinity of the melting point in a Differential Scanning Calorimeter (DSC) and Polarizing Microscope (PLM) Different temperature, respectively, the temperature-programmed temperature program was carried out to investigate the effect of four-arm polylactic acid on the crystallization behavior of linear polylactic acid.The results showed that with the four-arm polylactic acid content increased, The proportion of the formed crystals increases and the four-arm polylactic acid has the effect of promoting the crystallization of the blend, leading to an increase of the melting point in the melting process.Further studies have shown that the four-arm polylactic acid branch completely melted in the blend The structure can promote the formation of crystallization nucleation sites and promote the crystallization of the four-arm polylactic acid / linear polylactic acid blend. The partially-melted four-arm polylactic acid can greatly promote the crystallization ability of the blend, which is not completely melted Of the crystal nucleation caused by.