| Polymer blends have become a very important part of the commercialization of polymers. One of the reasons is that by combining two or more different existing polymers one can tailor compositions to meet specific end-use requirements without creating new molecules. However, most polymer pairs in blend systems are thermodynamically immiscible, feeding or in-situ forming compatibilization is often required. Reactive extrusion is most important way for achieving compatibilization blend of polymer pairs. In which, in-situ compatibilization, that is, the block or graft copolymer used as compatilization was formed in-situ, is common means for reactive blend; in-situ polymerization and in-situ compatibilization is a new process for reactive blend, which polymerized in-situ creating a homopolymer and a graft copolymer.In order to achieve the in-situ compatibilization of PP and other polymers, we must firstly achieve the functionalization modification of PP. Therefore, in the first part of the paper, the melting-grafting maleic anhydride onto polypropylene in the presence of styrene (St) as comonome was researched . The result showed that comonomer styrene might greatly improve the grafting degree of MAH and reduce the degradation of PP. And it was found that when St:MAH=l(mol/mol), the grafting degree of MAH reached maximum. Through the study on the mechanism, it was believed that when there wasn't styrene in the reactive system, MAH was grafted onto PP as single molecule after the degradation of PP. However, when there was styrene in the reactive system, MAH and St was grafted onto PP as alternate or CTC, and formed long chain of MAH and St. So the grafting degree of MAH was increased. At the same time, the reactive activity of St and CTC was higher than that of MAH, which led to graft onto PP before the degradation of PP. On the other hand, styrene may increase the cross linkage of PP. Therefore, the degradation of PP was reduced. These influencing factors included the DCP concentration, St concentration, MAH concentrate, reaction time, reaction temperature, screw speed and type of reactor on the grafting degree of MAH and MFR was also studied in this paper. Excepting the DCP concentration and processing parameters, the result showed that when maintaining MAH concentration and increasing St concentration, it was found that MFR still decreased. When maintaining St concentration and increasing MAH concentration, the grafting degree of MAH was slightly decreasing after increasing and MFR lied in the maximum. It can improve mechanical performance by adding PP-g-(St-MAH) to PP and PA6 blend systems.In Second part of the paper, we extended the field of application in-situ polymerization and in-situ compatilization technology to the synthesis of graft copolymerization of PS and PA6. Quantifications of the conversion of CL to PA6 were tested by elemental analysis basing on nitrogen, Gravimetry by solvent extraction (methanol, water, THF and acetone), Thermogravimetric analysis (TGA) and vacuum dryness at 140℃. It can be concluded that gravimetry by methanol extraction, TGA and vacuum dryness at 140℃ were suitable for analyzing the conversion. However, when analyzing the kinetics of CL to PA6, it should use the method of gravimetry by methanol extraction. The polymerization kinetics was followed up by the torque change of the polymerization systems. It was concluded that When it was below 200 ℃, little polymerization took place, when it was raised to 200℃, the polymerization started to proceed after 1.5min of mixing and the conversion of CL to PA6 grafts was about 90%; Theisocyanate content in the polystyrene had an effect not only on the rate of polymerization but also on the length of PA6 grafts in the copolymer; Increasing isocyanate content deceased the induction time of polymerization and the length of PA6 grafts; An increase in the amount of the catalyst (sodium caprolactam) led to a decrease in the induction time of polymerization and an increase in polymerization rate, but it had little effect on the conversion of CL to...
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