基于六氢邻苯二甲酸盐的α/β复合成核剂对聚丙烯性能的影响

Effect ofα/βcomplex nucleating agent based on hexahydrophthalate on properties of polypropylene

将α成核剂六氢邻苯二甲酸钙和β成核剂六氢邻苯二甲酸锌复合得到α/β复合成核剂体系,研究了其对等规聚丙烯(iPP)力学性能和结晶性能的影响,并用Avrami理论研究了成核iPP的等温结晶动力学。结果表明,α/β复合成核剂以特定比例复合可以同时提高iPP的刚性和韧性,其中在复合比例为7∶3时,拉伸强度提升了6.7%,弯曲模量提升了21.8%,冲击强度提升了108.2%。进一步研究了复合成核剂在iPP中的浓度效应,随着总添加量的增加,iPP的结晶温度逐渐增加,力学性能趋于稳定,在添加量达到0.4%(质量分数,下同)时基本不变,此时冲击强度提升了175.3%,弯曲模量提升了15.0%,拉伸强度提升了6.5%。等温结晶动力学的结果表明,复合成核剂体系的加入可以明显缩短iPP的结晶时间并且降低结晶所需的表面能。

Anα/βcomplex nucleating agent was prepared using the calcium salt of hexahydrophthalic acid as anαnucleat‑ing agent and the zinc salt of hexahydrophthalic acid as aβnucleating agent,and its effect on the mechanical properties and crystalline performance of isotactic polypropylene(iPP)was investigation.The Avrami theory was used to describe the isothermal crystallization kinetics of nucleated iPP.The results indicated that theα/βcomplex nucleating agent im‑proved the rigidity and toughness of iPP synchronously.When the mixing ratio was set to 7∶3,the nucleated iPP ob‑tained an increase in tensile strength by 6.7%,in flexural modulus by 21.8%,and in impact strength by 108.2%.The effect of concentration of theα/βcomplex nucleating agent in iPP was further studied.The crystallization tempera‑ture of iPP increased gradually with an increase in the total addition amount of the complex nucleating agent.The me‑chanical properties of the nucleated iPP tended to be stable when the addition amount of the complex nucleating agent reached 0.4 wt%.Its impact strength increased by 175.3%,flexural modulus increased by 15.0%,and tensile strength increased by 6.5%.The isothermal crystallization kinetic results indicated that the presence of theα/βcomplex nucleating agent system reduced the surface energy required for crystallization,shortening the crystallization time of iPP significantly.