β晶成核剂己二酸锌对等规聚丙烯成核效应的影响

Nucleating Efficiency of Highly Selective β-Nucleating Agent Zinc Adipate for Isotactic Polypropylene

合成了一种高效高选择性的等规聚丙烯（PP）β 晶成核剂己二酸锌（Adi-Zn）,研究了其用量对等规PP 成核效应的影响.力学性能测试结果表明,随Adi-Zn 用量增加,PP 的冲击强度先升高后趋于稳定,当Adi-Zn 用量为PP 质量的0.6% 时,成核PP 的冲击强度达到最大,是未加Adi-Zn 时的1.8 倍,而拉伸强度和弯曲弹性模量略有降低.采用广角X 射线衍射分析了Adi-Zn 对PP β 晶型含量的影响,结果表明,Adi-Zn 用量为PP 质量的0.2%~0.8% 时,β 晶型含量保持在95% 左右,说明Adi-Zn 具有较高的成核效率和选择性.利用差示扫描量热仪和偏光显微镜考察了Adi-Zn 对PP 结晶温度和晶体形态的影响,结果表明,当Adi-Zn 用量达到PP 质量的0.6% 时,成核PP 的结晶温度提高了3.1℃.同时随着Adi-Zn 的用量增加,Adi-Zn 诱导生成了更多的高亮β 晶型,并且明显细化了球晶尺寸.

A highly selective β-nucleating agent for isotactic polypropylene （iPP）,Zinc adipate （Adi-Zn）,was synthesizedand its nucleation efficiency for iPP was investigated. The mechanical properties tests indicate that with increasing Adi-Zn content,the impact strength of iPP first increases and then tends to be stable,when the content of Adi-Zn is 0.6% of iPP mass,the impactstrength of nucleated iPP reaches maximum and is 1.8 times of iPP without Adi-Zn,the flexural modulus and tensile strength ofnucleated iPP decreases slightly. The effect of Adi-Zn on the β-crystals content of iPP was characterized by using wide-angle X-raydiffraction and the analysis shows that the β-crystals content remain approximately 95% in the studied Adi-Zn content range from0.2% to 0.8% of iPP mass,which indicates Adi-Zn has high nucleation efficiency and selectivity. The dependences of the crystallizationtemperature and morphologies of iPP on the content of Adi-Zn were investigated by using differential scanning calorimetry andpolarized optical microscopy,respectively. The results show that the crystallization temperature of iPP with 0.6% Adi-Zn is increasedby 3.1℃ compared with iPP without Adi-Zn. Meanwhile,the more highlight β-crystals are induced and spherulite sizes of iPP aregradually decreased with increase of Adi-Zn content.