结晶聚合物的辐射效应——多官能团单体对LDPE的结晶成核作用

RAOIATION EFFECT ON CRYSTALLINE POLYMERS——NUCLEATION EFFECT OF POLYFUNCTIONAL MONOMERS ON CRYSTALLIZATION AND RADIATION CROSSLINKING OF LDPE

根据x射线、电镜、DSC和凝胶分数的测试结果,讨论了多官能团单体结构对低密度聚乙烯聚集态结构的影响以及结晶度与辐射交联(或剂量)的关系。发现由于单体的存在导致低密度聚乙烯结晶度增加而结晶尺寸变小(即结晶成核效应);成核效应越大,增强辐射交联的效果也越大。添加具有高结晶成核作用的单体有利于低密度聚乙烯的辐射交联,同时也加速其结晶结构的破坏。

The nucleation effect of some polyfunctional monomers on radiation crosslinking oflow density polyethylene (LDPE) has been studied. The effect of monomer structure onthe moiphological structure of LDPE and the relationship between radiation crosslinkingand crystalline density of LDPE with different monomer were discussed according to theresults of WAXD, TEM, DSC and gel fraction measurements. It is found that in thepresence of monomer the crystalline content of LDPE was larger and the crystalline sizewas smaller than that of LDPE alone, and the greater the nucleation effect, the more acce-lerated the radiation crosslinking effect for LDPE. It is considered that both crystallinedensity and size are the primary (basis) factors in radiation crosslinking of crystallinepolymers, and the crystalline damage caused by irradiation is closely relevent to the Surfacearea between crystalline and amorphous regions of the polymer