稀土β成核剂对高抗冲聚丙烯性能的影响

通过力学性能测定、示差扫描量热和广角X射线衍射等方法,考察了稀土β成核剂(W BG)对高抗冲聚丙烯(H IPP)力学性能和结晶行为的影响。实验结果表明,加入W BG可使H IPP的冲击强度、断裂伸长率和热变形温度大幅度提高。当W BG添加量(质量分数)为0.15%时,试样中β晶的相对含量达到90%以上。结晶动力学研究表明,加入W BG导致H IPP体系在非等温结晶条件下结晶速率减慢,但W BG具有明显的异相成核作用,当W BG添加量为0.10%时,可使初始结晶温度升高10℃以上。含W BG的H IPP体系经多次加热-冷却处理后β晶的相对含量未发生显著变化,说明W BG具有良好的加工稳定性。

Effects of Rare Earth β Nucleating Agent on Properties of High-Impact Polypropylene

Effect of rare earth β nucleating agent(WBG) on mechanical properties and crystallization behavior of high-impact polypropylene(HIPP) was investigated by means of DSC and WAXD.WBG is an effective β-form nucleating agent in transition of HIPP crystalline form from α to β-form.When addition of WBG is 0.15%(mass fraction),relative content of β-form in the sample reaches more than 90%.Addition of WBG remarkably increases impact strength,elongation at break,rupture strength and heat distortion temperature of HIPP,but slightly decreases its elastic modulus and yield strength.Concerning non-isothermal crystallization behavior of HIPP,addition of 0.10%(mass fraction) WBG decreases crystallization rate slightly but increases initial crystallization temperature for more than 10 ℃,which shows effect of WBG in nucleation.When HIPP with WBG after experiencing multi heating-cooling cycles in processing,no obvious change of WBG content was observed,which indicated good processing stability of WBG.