| PEB-g-MAN, synthesized by suspension grafting copolymerization of methyl methacrylate and acrylonitrile from Poly(ethene-co-l-butene) (PEB), was blended with styrene-acrylonitrile copolymer (SAN) to prepare a high impact plastic ABMS. ABMS is characterized by excellent weatherability and yellow discoloration resistivity because of no double bond in molecule chain of PEB. ABMS is a potential engineering plastic, will substitute ABS if it can be in industrial production and this high performance plastic hasn't been reported yet.The effect of fAN(fAN was equal to AN/MMA-AN), fPEB(fPEB was equal to PEB/(PEB+MMA-AN)),content of initiator BPO,content of solvent toluene, main dispersant PVA,assistant dispersant, water/oil ratio, reactive temperature, reactive time and content of additional monomer styrene on the monomer conversion ratio (CR), average grafting ratio (GR), grafting efficiency (GE), rubber's grafting ratio(GRR), ture grafting ratio(GRT) of copolymerization and the notched impact strength of ABMS were investigated systematically. The best synthetic conditions which made the notched impact strength of ABMS to reach the highest level were obtained by optimizing grafting reaction condition. The results showed that fAN,GRR were the key factors influencing on the toughening effect of PEB-g-MAN on SAN resin. The notched impact strength of ABMS was 63.3 kJ/m2 with PEB-g-MAN synthesize by optimized condition and CR, GR, GE, GRR, GRT of the PEB-g-MAN was 91.4%,27.7%, 38.1%,79.5%,34.9% respectively.The components of the grafted copolymer were separated by different solvent and were qualitative/quantitative analysis by using Fourier transform infrared spectroscopy (FTIR).The results showed that the main reactions in PEB/MMA-AN grafting reaction system were graft copolymerization of PEB/MMA-AN, graft polymerization of PEB/MMA, copolymerization of MMA and AN, homopolymerization of MMA, and there were no grafting polymerization of PEB/AN, homopolymerization of AN and crosslinking reaction of PEB. Through the study of effects of reaction time on reaction behavior of PEB/MMA-AN, it was found that the first stage of polymerization was mainly graft reaction generating graft copolymer, the second stage of polymerization was competitive reaction between graft copolymerization and copolymerization, and the third stage of polymerization was mainly copolymerization.The quantitative relationship of fAN on AN unit-to-MMA unit weight ratio in g-MAN chains/non-grafted components had been established by using FTIR quantitative analysis method, and it was found that both the average weight fraction of AN unit in g-MAN (FAN-1) and the average weight fraction of AN unit in non-grafted components(FAN-2) were less than fAN. GPC and DMA analysis showed that the miscibility between PEB-g-MAN and SAN resin was best, PEB-g-MAN had a best toughening effect on SAN resin while FAN-1 was 21.6wt% and PEB-g-MAN having a lower molecule weight and a high GRR.TEM and SEM analysis showed that main factors influencing on phase struture and toughening mechanism of ABMS were the polarity of graft chain g-MAN and GRR. PEB-g-MAN had a highest GRR and a proper polarity graft chain when fAN was 25wt%, fPEB was 55%, and the phase structure of ABMS with this PEB-g-MAN was co-continue structure with occlusion structure (PEB occluded plastic particle), the toughening machenism was severe shear yielding. When the PEB content was low, the toughening mechanism of the blends was branch and termination of crack with slight cavitations, then changed into extensive cavitations,severe shear yielding, and finally changed into shear yielding accompanied by cavitations as PEB increasing.TG and DTG analysis showed that thermal stability of SAN resin was improved after being blending with PEB-g-MAN. The thermal oxidative aging and accelerated weather aging results showed that the aging property of ABMS was better than ABS.
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