聚己内酯在聚己内酯/聚乙烯基甲基醚共混体系中的结晶研究

通过示差扫描量热(DSC)、广角X射线衍射(WAXD)、小角X射线散射(SAXS)研究了聚己内酯(PCL)/聚乙烯基甲基醚(PVME)共混体系中PCL的结晶行为.研究结果表明,共混聚合物中PCL的结晶度几乎不随体系的组成而发生变化.共混物中PVME的存在没有改变PCL的晶体结构,但是随着PVME含量的增加,片晶之间的距离则大,这主要是由于非晶层增厚引起的.

STUDY ON CRYSTALLIZATION OF POLY(ε-CAPROLACTONE) IN POLY(ε-CAPROLACTONE)/POLY(VINYL METHYL ETHER) BLENDS

The crystallization behaviors of poly(ε-caprolactone)(PCL)in poly(ε-caprolactone)(PCL)and poly-(vinyl methyl ether)(PVME)blends were investigated by POM,DSC,WAXD,SAXS.POM results indicated that spherical crystal morphology was present during isothermal process,and the spheric growth rates were reduced with increasing the contents of PVME in PCL/PVME blends.It was found that the crystallinity of PCL in the blends remained almost constant regardless of the blend composition,but it was dependent on preparation technique.Solution-crystallization was found to be a technique capable of increasing crystallinity levels for some compositions.The melting behavior of the blends is a rather complex process.Both solution-crystallized samples and isothermal-crystallized samples exhibited a single endotherm.Oppositely,melting-crystallized samples exhibited dual-melting endotherms whose mangnitudes vary with blend compositions.On the basis of WAXD and SAXS experiments,it is found that the crystal structure is unchanged,but the long period increases with increasing the content of PVME because of the thickening of the amorphous layers.