动态保压注射成型中POE-g-MAH 对PA1010-PP 共混物的增容作用

Compatibilization effect of POE-g-MAH on PA1010-PP blends obtained via dynamic packing injection molding

  • 摘要: 以马来酸酐接枝乙烯-辛烯共聚物(POE-g-MAH)作为增容剂, 采用熔体共混的方法制备了PA1010-PP共混物, 通过扫描电镜(SEM)、 力学性能和差示扫描量热(DSC)测试, 研究了动态保压注射成型中POE-g-MAH对PA1010-PP共混物的增容作用。力学性能测试结果表明, 在注射成型过程中施加剪切应力, 明显提高了共混物的拉伸和冲击性能。SEM结果表明, 剪切诱导制品产生多层次结构, 而且分散相相区尺寸显著减小, 分散更趋均匀, 相界面更加模糊。DSC结果表明, 剪切应力作用下, 当POE-g-MAH的质量分数达到15%时, PP出现2个结晶峰, 即出现异相成核结晶和均相成核结晶, PP均相成核结晶的出现从另一个方面表明动态试样中分散相PP尺寸小于静态试样。剪切应力作用下增容作用的提高归因于剪切应力作用下独特相形态的形成。

     

    Abstract: Various polyamide-polypropylene (PA1010-PP) blends were prepared by melt mixing using maleic anhydride-grafted ethylene-octene copolymer (POE-g-MAH) as a compatibilizer. In order to investigate the compatibilizing effect of POE-g-MAH on PA1010-PP blends obtained via dynamic packing injection molding (DPIM), morphologies, mechanical and crystallizing properties of the blends were characterized by means of scaning electron microscopy (SEM), mechanical testing and differential scaning calorimetry (DSC), respectively. It is found the tensile strength, tensile modulus and notched impact strength largely increase by applying shear stress during injection molding. SEM results show a remarkable decrease of domain size, more uniform dispersion and more fuzzy interface of the dynamic molded specimens, which indicates that shear stress can accelerate compatibilization. DSC results show that two crystalline peaks appear in dynamic samples when POE-g-MAH reaches 15%, the crystallization of PP at the lower temperature should be assigned to homogeneous nucleation, the other one is heterogeneous nucleation. The appearance of homogeneous nucleation demonstrates that the size of PP particles is very fine in the matrix. The enhancement of compatibilization effect of POE-g-MAH on PA1010-PP blends under shear stress could be due to the effect of shear-induced particular morphologies.

     

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