透明耐热聚乳酸共混材料的制备与性能研究

摘要

Poly(L-lactide) (PLLA) was melt blended with poly(methyl methacrylate) PMMA. In this way, transparent blend was produced. It is found that PLLA/PMMA blend has high miscibility in the amorphous state because only single Tg is observed in the DSC measurement. The bending strength, impact strength and tensile strength of PLLA/PMMA blends are higher than those of pure PLLA and pure PMMA. Avrami index shows that the adding of PMMA does not change the nucleation and crystal growth mechanism of PLLA. But the crystallization rate of PLLA is lowered. Vicat transition temperature of the blend will increase when the PMMA content rises. Thermal treatment was also used to prepare translucent PLLA/PMMA blend of high heat resistance.Best condition of thermal treatment has been decided.%采用熔融共混法制备聚乳酸(PLLA)/聚甲基丙烯酸甲酯(PMMA)透明共混材料.DSC测试结果表明,共混材料只出现一个玻璃化转变温度,说明PLLA/PMMA共混材料在宏观上不发生相分离.力学性能研究发现,PLLA/PMMA共混材料的弯曲强度、抗冲击强度和拉伸强度均优于纯PLLA及纯PM-MA.Avrami指数表明,PMMA的加入未改变PLLA的成核机理与晶体生长方式,但PLLA的结晶速率降低.PLLA/PMMA共混材料的维卡转变温度随PM-MA含量的增加而提高.还通过热处理法制得半透明高耐热PLLA/PMMA共混材料,并确定了最佳热处理条件.