高分子量无规聚丙烯的表征及其硫化性能研究

Characterization of high molecular weight atactic polypropylene and preliminary study on its curing properties

用五甲基环戊二烯三苄氧基钛与甲基铝氧烷催化体系合成出高分子量弹性聚丙烯(El-APP)。用核磁共振碳谱、差示扫描量热法、动态力学分析等测试表明,该产物为高分子量无规聚丙烯(APP),呈现橡胶的动态力学行为,并具有良好热稳定性。El-APP的拉伸强度为2.8MPa,伸长率高达2200％,具有良好弹性。采用过氧化物对其进行硫化研究,结果表明,El-APP正硫化较短,无硫化返原现象,硫化之后拉伸强度提高,永久变形大幅下降。

Elastomeric atactic polypropylene (El - APP) was synthesized by the catalyst composed of η5 - pentamethyl-cyclopentadientyl tribenzyloxy titanium and methylaluminoxane in heptane solvent. The products were characterized by nuclear magnetic resonance, differential scanning calorimetry, gel permeation chromatograph, dynamic mechanical analysis and thermogravimetry. The results indicated that the products were high molecular weight atactic polypropylene which showed dynamic mechanical behavior of rubber and good thermal stability. The tensile strength of the El - APP was 2.8 MPa and the elongation at break was up to 2 200% , indicating that the El - APP was a good elastomer. The El - APP so prepared was vulcanized by hyperoxide. The curing time for El - APP was relatively shorter and the curing curve of the El - APP didn't show a reversion. The tensile strength of the El - APP increased and the permanent set decreased after vulcanization.