The compatibitily and morphology of HIPS/PC and HIPS g GMA/PC blends were studied.The compatibility and morphology of HIPS/PC blends were characterized by DSC and SEM,respectively.The result of DSC shows that T g of PS doesn’t change with the blend composition,and T g of PC decreases with the increase in weight fraction of HIPS,which indicates that the PC/HIPS blend is a partially miscible system.Results of SEM indicate that the decrease in T g of PC results from PS interpenetrating into the phase of PC,and no change in T g of PS results from PC not interpenetrating into the phase of PS.The copolymer of HIPS g GMA was prepared by reactive grafting method.The IR spectrum shows that GMA is grafted on the chain of HIPS.The compatibility and morphology of HIPS g GMA(35)/PC(65) were studied by DSC and SEM.PC(65)/HIPS g GMA(35) blend exhibits reduced size of disperse phase,enhanced interface adhesion and lower T g of PC phase as compared with the PC(65)/HIPS(35) blend.It implies that HIPS g GMA is an effective compatibilizer of the HIPS/PC blend.
The effect of temperature on the characteristic of Fourier Transform Infrared(FTIR),the dependence of the average molecular weight and the polydispersity on the annealing temperature and the relationship between linear expansion coefficients and temperature of poly(propylene carbonate) end-capped with maleic anhydride(MA-PPC) were investigated.The vibration peak of hydroxyl group at 1714?cm -1 in the FTIR spectra,which belongs to the carboxyl end-group in MA-PPC,decreases with increasing the temperature of the sample and it disappeared totally when the sample was heated over 70℃.The average molecular weight of MA-PPC almost doubled when the sample was annealed at 110~150℃ for 30 min,however the polydispersity was maintained roughly.A new relaxation transition at about 80℃ was detected on the curve of the linear expansion coefficient versus temperature that is the characteristic of macromolecular coupling or crosslinking reaction.These results confirmed that the macromolecular coupling reaction was carried out between the end carboxyl groups of MA-PPC when the sample was heated over 70℃.