The effects of CaCO\-3 on the crystallization behavior of polypropylene (PP) were studied by means of DSC and WAXD.The average sizes of the CaCO\-3 powders used were 0\^1?μm (UC) and 0\^5?μm (GC),respectively.The PP...The effects of CaCO\-3 on the crystallization behavior of polypropylene (PP) were studied by means of DSC and WAXD.The average sizes of the CaCO\-3 powders used were 0\^1?μm (UC) and 0\^5?μm (GC),respectively.The PP/CaCO\-3 composites at compositions of 1?phr and 10 phr were investigated.The results showed that the addition of CaCO\-3 reduced the supercooling,the rate of nucleation and the overall rate of crystallization (except for the 10?phr UC/PP sample).The crystallinity of PP was increased and the size distribution of the crystallites of α \|PP was broadened.On the other hand,the crystallization rate of 10?phr UC/PP is 1\^5 times higher than that of neat PP.It has an overall rate of crystallization 2 times as much as that of the neat PP and has the maximum crystallinity.The sizes of crystallites and the unit cell parameters of α \|PP were varied by the addition of CaCO\-3. β \|PP was formed by addition of GC and was not detected by addition of UC.The differences of crystallization behaviors of PP might be attributed to the combined effects of the content and size of CaCO\-3 filled.展开更多
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 P...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.展开更多
The effects of self seeding nucleation on the crystallization behavior and properties of polypropylene (iPP) were studied. DSC results indicated that the crystallization temperature of iPP increased obviously after th...The effects of self seeding nucleation on the crystallization behavior and properties of polypropylene (iPP) were studied. DSC results indicated that the crystallization temperature of iPP increased obviously after the process of self seeding nucleation. The results of polarized light microscopy showed that the spherulite size decreased markedly, as a result, the mechanical properties and the transparency of iPP were all improved.展开更多
文摘The effects of CaCO\-3 on the crystallization behavior of polypropylene (PP) were studied by means of DSC and WAXD.The average sizes of the CaCO\-3 powders used were 0\^1?μm (UC) and 0\^5?μm (GC),respectively.The PP/CaCO\-3 composites at compositions of 1?phr and 10 phr were investigated.The results showed that the addition of CaCO\-3 reduced the supercooling,the rate of nucleation and the overall rate of crystallization (except for the 10?phr UC/PP sample).The crystallinity of PP was increased and the size distribution of the crystallites of α \|PP was broadened.On the other hand,the crystallization rate of 10?phr UC/PP is 1\^5 times higher than that of neat PP.It has an overall rate of crystallization 2 times as much as that of the neat PP and has the maximum crystallinity.The sizes of crystallites and the unit cell parameters of α \|PP were varied by the addition of CaCO\-3. β \|PP was formed by addition of GC and was not detected by addition of UC.The differences of crystallization behaviors of PP might be attributed to the combined effects of the content and size of CaCO\-3 filled.
文摘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.
文摘The effects of self seeding nucleation on the crystallization behavior and properties of polypropylene (iPP) were studied. DSC results indicated that the crystallization temperature of iPP increased obviously after the process of self seeding nucleation. The results of polarized light microscopy showed that the spherulite size decreased markedly, as a result, the mechanical properties and the transparency of iPP were all improved.
