聚丙烯多单体接枝共聚物的结晶行为

Crystallization behavior of multi-monomer graft copolymers of polypropylene

通过固相接枝法制备聚丙烯(PP)与马来酸酐、甲基丙烯酸甲酯和丙烯酸丁酯的多单体接枝共聚物(PPTM)。采用差示扫描量热法、X射线衍射和偏光显微镜等研究接枝支链对接枝共聚物结晶行为的影响,并计算接枝共聚物的晶胞参数。接枝支链能诱导PPTM的异相成核,形成β晶型,也能阻碍结晶的进行。接枝支链诱导PPTM形成β晶型需要合适的支链长度。PPTM的微晶尺寸和晶胞参数都受到接枝支链的影响。PPTM的c轴(晶体生长方向)的晶胞参数比PP的稍大。

The multi-monomer graft copolymers of polypropylene（PPTM） were synthesized by solid phase graft of maleic anhydride, methyl methacrylate and butyl acrylate onto PP. Differential scanning calorimeter（DSC）, X- ray diffractometer（XRD） and polarized light microscope（PLM） were used to research the effect of the grafted side chains on the crystallization behavior of PPTM. The lattice parameters were also calculated based on the XRD pattern. The crystalline in PPTM, grafted side chains induced the heterogeneous-nucleation and the formation of 13 but hindered the crystallization of PPTM. The grafted side chains should be in appropriate length to induce the formation of β crystalline in PPTM. Both crystallite size and lattice parameters were affected by the grafted side chains. The lattice parameters of PPTM in the c axis（direction of the crystal growth） were higher than those of PP.