Graphene / Stability Of Isotactic Polybutene-1 And The Composite Material After Aging Heat Polycarbonates

In this dissertation, graphite oxide was prepared by Hummers methods, and graphene was manufactured by rapid thermal expansion of graphite oxide. Graphene/isotactic polybutylene-1(iPB-1) composite was prepared by coating and solution coagulation, respectly. Graphene has a good dispersibility in the composite prepared by solution coagulation.With the content of graphene increasing from0%to1.07%, crystallization peak temperature of composite gradually moved to high temperature, increasing from66.7℃to77.4℃. The full width at half maximum reduced from9℃to7.3℃. Avrami index calculated by Jeziorny equation of composite (w=1.07%) was greater than3; F(T) calculated by mo method decreased with adding graphene; Activation energy (-128.5kJ/mol) of the crystallization process of composite was less than activation energy (-95.7kJ/mol) of the crystallization process of iPB-1. These studies on non-isothermal crystallization kinetics showd that graphene played the role of heterogeneous nuclear, and accelerated the crystallization of polybutylene-1.Polarizing microscope observation showed that with the content of graphene increasing from0%to1.07%, the number of spherulite increased, and the size of spherulite decreased. In the process of isokinetic cooling crystallization, the temperature of forming spherocrystal in composite(w=0.56%) and iPB-1is94℃and90℃, respectly; The temperature of visual field covered by spherocrystal of composite and iPB-1was83℃and74℃, respectly. As nucleating agent, Graphene accelerated the crystallization of polybutylene-1and raised the crystallization temperature Polycarbonate(PC) was aged under hot air and hernia light, respectly. After different aging time under hot air and hernia light, polycarbonate (PC) was analyzed by thermogravimetry under nitrogen and Air atmosphere, and its kinetics of thermal degradation by Coats-Redfern method and Freeman-Carroll method.The temperature of biggest loss rate and relative loss weight content of PC after thermal-oxidative aging under nitrogen atmosphere was decreased firstly. after aging120h, these temperature began to increase and reached the highest value at168℃. TG curve of PC before and after aging under air atmosphere was divided into three stages. The initial weight loss temperature increased firstly and decreased lately. The studies on thermal degradation kinetics have shown that in the initial stage of aging, thermal degradation activation energy decreased, the PC thermal stability decreased and the mian react was main chain scission and terminal off; Later in the aging, the thermal degradation of the activation energy increases, its thermal stability increased, and there was crosslink structure forming. There was not obvious regularity on temperature parameters of TG under nitrogen and air atmosphere of PC after photo-oxidative aging. The studies on thermal degradation kinetics have shown that the PC thermal stability decreased gradually with aging time.The observation of the surface morphology of PC after thermal-oxidative aging showed that there were some ribbon defects on PC caused by thermal-oxidative aging. The number of the white strips increased at the early stage of the aging process, and reduced after120h.