稀土镧系单核金属化合物β晶成核剂对等规聚丙烯成核效应的影响

Efficiency of a Novel Rare Earth Compound as β Nucleating Agent of Isotactic Polypropylene

考察了稀土镧系单核金属化合物（HPALa）β晶成核剂对等规聚丙烯（iPP）成核效应的影响。广角X射线衍射表征结果显示，HPALaβ晶成核剂能诱导iPP从α晶型转变成β晶型；成核iPP中β晶型iPP的含量取决于结晶过程中的冷却速率和等温结晶过程中的结晶温度，当HPALa添加量（W（HPALa），占iPP的质量分数）为0．20％时适宜的结晶温度为135℃，当W（HPALa）=0．05％时适宜的冷却速率为20～40℃／min。HPALa卢晶成核剂可同时改善iPP的刚性和韧性，当W（HPALa）=0．50％时，成核iPP在室温（25℃）下冷却结晶，与空白iPP相比，常温（23℃）抗冲强度提高了220％，弯曲模量提高了15％，拉伸强度提高了3％；当W（HPALa）增至1．0％时，成核iPP的力学性能基本保持不变。

Efficiency of a novel rare earth lanthanide mono-metal compound （HPALa） as β nucleating agent in isotactic polypropylene （iPP） crystallization was investigated. Crystallization temperature and cooling rate exerted substantial effects on content of iPP t-form crystals. When addition amount of HPALa （ based on iPP mass ） is 0.20%, the optimum crystallization temperature of inducing transformation of a-from crystals to β-form is 135 ℃ and when addition amount is 0.05% the optimum cooling rate is 20 -40 ℃/min. The addition of HPALa as nucleating agent enhances the mechanical properties of iPP evidently. For example, when amount of addition is 0.50% in comparing with the blank impact strength of iPP can be raised by 220% （23 ℃ ）, flexural modulus by 15%, and tensile strength by 3 %. Mechanical properties of nucleated iPP trend to maintain nearly constant after addition amount of HPALa increases to 1.0%.