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采用三羟甲基丙烷(TMP)和马来酸酐(MA)制备多官能度烯类支化单体单三羟甲基丙烷三马来酸单酯(MTPTM)。MTPTM与甲基丙烯酸(MAA)在水溶液中通过自由基聚合,制备超支化聚合物。采用NMR表征了MTPTM和超支化聚合物的结构。考察了MAA和MTPTM单体摩尔比对超支化聚合物相对分子质量、水溶液黏度、热稳定性以及玻璃化转变温度的影响。结果表明,随MAA单体用量增加,聚合物相对分子质量及其分布先降后升,n(MTPTM)∶n(MAA)=1∶9时出现最小值(Mw=2.09×104,Mw/Mn=1.66),产物水溶液黏度也呈现先降后升的趋势,并在n(MTPTM)∶n(MAA)=1∶6时出现最小值。而玻璃化转变温度则先升后降,n(MTPTM)∶n(MAA)=1∶9时出现最大值(Tg=274.5℃),MAA单体比例增加,有助于超支化聚合物热稳定性提高。
Trimethylolpropane trimaleic acid monoester (MTPTM) was prepared from trimethylolpropane (TMP) and maleic anhydride (MA). MTPTM and methacrylic acid (MAA) were prepared by radical polymerization in aqueous solution to prepare hyperbranched polymers. The structure of MTPTM and hyperbranched polymers was characterized by NMR. The effects of molar ratio of MAA and MTPTM on the molecular weight, viscosity, thermal stability and glass transition temperature of hyperbranched polymers were investigated. The results showed that the molecular weight and its distribution of the polymer first decreased and then increased with the increase of the MAA monomer. The minimum value (Mw = 2.09 × 104, Mw / Mn = 1.66). The viscosity of product aqueous solution also showed the trend of decreasing firstly and then increasing, and the minimum appeared at n (MTPTM): n (MAA) = 1: 6. While the glass transition temperature firstly increased and then decreased. The maximum value (Tg = 274.5 ℃) appeared when n (MTPTM): n (MAA) = 1: 9 and the MAA monomer proportion increased, which contributed to the thermal stability of the hyperbranched polymer Sex improved.