s-PB/TPI釜内原位聚合共混物的非等温结晶动力学

Nonisothermal crystallization kinetics of syndiotactic 1,2-polybutadiene/trans-1,4-polyisoprene blends of in-situ polymerization

采用2种负载型催化体系在反应釜内原位合成了间同聚丁二烯(s-PB)及s-PB/反式-1,4-聚异戊二烯(TPI)(80/20)共混物。用DSC方法研究了s-PB及共混物的非等温结晶行为,结果表明:Jeziorny修正的Avrami法和Mo法对s-PB及s-PB/TPI(80/20)共混物的非等温结晶行为有较好的适用性,Ozawa法则存在一定的缺陷。s-PB及其共混物的结晶活化能分别为-253 kJ/mol和-310 kJ/mol。TPI的加入降低了s-PB的结晶速率,使得共混物的结晶活化能绝对值增大。

s-PB, s-PB/TPI（80/20） blends were prepared in the reactor with supported catalysts SiO2/Co（naph）2-Al（i-Bu）3-CS2 and MgCl2 · SiO2/TiCl4- Al（i-Bu）a. The nonisothermal crystallization kinetics of s-PB and s-PB/TPI were investigated by DSC. The results showed that the Avrami method modified by Jeziorny and the Mo method are feat, but the Ozawa method has a blemish to s-PB. The activation energies have been evaluated by Kissinger method to be -253 kJ/mol and -310 kJ/mol for s-PB and the blends. The TPI has decreased the crystal rates. The absolute value of activation energy of crystallization of s-PB/TPI blends is higher than s-PB.