Thermogravimetric studies on poly(methyl methacrylate), poly(tetrahydrofuran) and their blends

摘要

TG studies are given for PMMA prepared by radical polymerization, PTHF prepared by cationic polymerization, and their blends. A procedure is proposed for determining the activation energy, frequency factor, and the order of events corresponding to the respective stages of the multistage TG curves. The order of the initial event of PMMA is not the 1~(st). It is shown for this discussion that the relationship between mass loss and time of the 2~(nd) order reaction is similar to that of the depolymerization including the vaporization process at the earlier times. Some of TG curves of PTHF are not dependent on the heating rate. This independence depends on the size of sample. The order of event of PTHF, which is obtained from TG curves dependent on the heating rate, is the 0~(th). The event order equal to the 0~(th) reflects major contribution of varporization in the event. The TG behaviors shown by the procedure mentioned above for the PMMA/PTHF blends with the smaller PMMA or PTHF contents cancel those of PMMA or PTHF.