摘要
通过熔融共混制备了聚乳酸/聚丁二酸丁二醇酯/聚乙二醇(PLA/PBS/PEG)三相共混物,利用扫描电子显微镜、平板流变仪、差示扫描量热仪、动态力学热分析仪、万能拉力试验机和简支梁冲击试验机分别研究了PEG含量对PLA/PBS(80/20)合金微观结构与性能的影响。结果表明,添加PEG组分能够降低PBS分散相的尺寸、均化尺寸分布、增加界面层厚度;随着PEG含量增加,PLA/PBS/PEG共混物复数黏度降低并且剪切变稀行为更加显著,共混物中PLA组分的玻璃化转变温度和冷结晶温度降低幅度随着PEG含量增加而增大,同时结晶度增加。动态力学热分析曲线显示PLA与PBS组分的玻璃化转变温度相互靠近,说明PEG能够促进PLA与PBS的相容性。力学性能结果表明,添加PEG组分到PLA/PBS(80/20)共混物中,可以在拉伸强度降低幅度不大的情况下大幅度提高共混体系的韧性。
Polylactic acid/polybutylene succinate/polyethylene glycol(PLA/PBS/PEG) triple-phase blends were prepared by melt blending. And effects of PEG contents on the microstructure and properties of PLA/PBS(80/20) blends were investigated by SEM, rotational rheometer, differential scanning calorimeter(DSC), dynamic thermomechanical analyzer(DMA), universal tensile tester and Charpy impact tester, respectively. The results show that the addition of PEG can reduce the size and homogenize size distribution of the dispersed phase, increase the thickness of the interface layer. With the increase of PEG content, the complex viscosity of PLA/PBS/PEG blends decreases and the shear thinning behavior becomes more significant. Furthermore, the declining degree of glass transition temperature and cold crystallization temperature of the PLA component increases with the increase of PEG content, meanwhile, the crystallinity of blends increase. The DMA curves show that the glass transition temperatures of PLA and PBS components are close to each other, indicating that PEG could promote the compatibility of PLA with PBS. The results of mechanical properties show that the addition of PEG component to PLA/PBS(80/20) blends could remarkably improve the toughness of the blends while the tensile strength is reduced gently.
引文
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