α-甲基苯乙烯/苯乙烯/马来酸酐三元共聚物功能化聚丙烯及增容聚丙烯/尼龙6共混体系的研究

FUNCTIONALIZATION OF POLYPROPYLENE AND COMPATIBILIZATION OF POLYPROPYLENE/NYLON 6 BLENDS WITH α-METHYL STYRENE/STYRENE/MALEIC ANHYDRIDE TERNARY COPOLYMER

采用溶液聚合的方式合成了α-甲基苯乙烯/苯乙烯/马来酸酐三元共聚物(简称为PASM),研究了单体组成、反应温度和时间等因素对共聚的影响,并进一步研究了三元共聚物对聚丙烯的功能化作用和对聚丙烯/尼龙6(PP/Ny6)共混体系的原位增容作用.GPC和TG等技术对PASM的表征结果显示,随着单体组成中α-甲基苯乙烯(AMS)含量的减少,聚合物产率呈上升趋势,同时共聚物分子量增大;共聚反应在50～75℃温度范围内遵循一般的自由基共聚反应机理,当反应温度升高到70℃时,共聚物发生解聚反应;共聚物的热稳定性随着共聚物组成中AMS含量的增加而降低.FTIR分析结果表明,通过熔融接枝反应过程,可以实现PASM与聚丙烯的接枝反应;而SEM分析结果则显示将少量的(3 wt%)PASM加入PP/Ny6共混体系,就可以起到原位增容作用,使分散相Ny6的粒径显著减小.

The ternary copolymers of α-methyl styrene（AMS）/styrene（St）/maleic anhydride（MAH）（referred to as PASM） were synthesized by solution polymerization.The effects of factors,such as monomer composition,temperature and time of copolymerization,were studied systematically.The copolymers of PASM were characterized by gel permeation chromatography（GPC）,Fourier transform infrared spectroscopy（FTIR） and thermogravimetery（TG）.The results indicated that the lower AMS feed ratio led to higher molecular weights and higher monomer conversion as well.When the polymerization temperature went over 70℃,the depolymerization occurred.The higher the temperature,the more serious the depolymerization.TG revealed that thermal stability of the copolymers decreased with increasing the AMS content in the copolymers,which indicated that the degradation was mainly caused by the chain scission of AMS-containing structures.The graft reaction of PASM onto polypropylene（PP） in molten state was investigated,and the functionalized production was confirmed by the FTIR spectra.Through SEM,the in situ compatibilization of polypropylene/nylon 6（PP/ Ny6） blends with PASM was observed.The results indicated that with little PASM（PP/Ny6/PASM = 80/20/ 3 wt%） being added into PP/Ny6 blends,the in situ compatibilization role can be found distinctly,and the domain of the dispersed phase Ny6 reduced significantly.