马来酸酯烯类支化单体合成及其与甲基丙烯酸的共聚

Synthesis of Maleate Allyl Branching Monomer and Its Copolymerization with Methacrylic Acid

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。

Mono-trimethylolpropane trimaleate（MTPTM） was prepared by esterification from trimethylolpropane（TMP） and maleic anhydride（MA）.MTPTM was employed as allyl branching monomer to copolymerize with methacrylic acid to prepare hyperbranched copolymers（HBCs）.The structure of MTPTM and result polymer were characterized by NMR.The effects of feed ratio on HBCs properties including molecular weight and its distribution,aqueous solution viscosity,thermal stability and glass transition temperature were investigated.The results indicated：with n（MTPTM）：n（MAA） increasing from 1：3 to 1：15,HBCs molecular weight and its distribution showed a minimum（Mw=2.09×104,Mw/Mn=1.66） for n（MTPTM）：n（MAA）=1：9,aqueous solution viscosity manifested the same trend with a minimum at n（MTPTM）：n（MAA）=1：6,glass transition temperatures showed an reverse trend with a maximum（Tg=274.5 ℃） for n（MTPTM）：n（MAA）=1：9.The increasing of MAA molar ratio was helpful to the enhancement of HBCs thermal stability.