侧链为端羧基聚乙二醇的梳形聚氨酯的合成与表征

Synthesis of Comb-like Polycarbonate Urethane with Carboxyl-terminated Polyethylene Glycol Side Chains

以L-赖氨酸、乙二胺和端羧基聚乙二醇(PEG)为原料合成一种带聚乙二醇侧链的二元胺扩链剂(Lys-NH-PEG),然后以4,4'-二苯基甲烷二异氰酸酯(MDI)和Lys-NH-PEG为硬段,聚碳酸酯二醇(PCD)为软段,制备一种含端羧基聚乙二醇侧链的梳形聚氨酯.对所合成聚氨酯材料进行傅立叶变换红外光谱(FTIR)、氢核磁共振谱(1H-NMR)、凝胶渗透色谱(GPC)测试,测试结果表明得到了目标聚合物.该聚合物能在水中形成胶体,并能化学接枝白蛋白,表明所合成的聚氨酯的PEG侧链端羧基具有反应活性.这种具有可反应性的聚氨酯为进一步接枝生物分子以提高生物相容性提供了广阔的空间.

A diamine with carboxyl-terminated polyethylene glycol （PEG） side chains （Lys-NH-PEG）was synthesized as chain extender for polyurethanes （PUs）, using L-lysine, ethylenediamine and PEG bis- （carboxymethyl） ether as raw materials. Further to this, a comb-like polycarbonate urethane with PEG side chains （PCU-L-P） was synthesized using Lys-NH-PEG and 4,4＇-diphenylmethane diisocyanate （MDI） as hard segment, and polycarbonate diol as soft segment. Fourier transform infrared spectroscopy （FTIR） and proton nuclear magnetic resonance （^1H-NMR） were used to confirm the chemical structure of PCU-L-P,whose number-average molecular weight was about 38000 determined by gel permeation chromatography （GPC）. The solution of PCU-L-P （in dimethylformamide） can be transformed into hydrocolloid stabilized by the hydrophilic PEG side chains,with a mean particle size of about 213 nm and a zeta potential of -19 mV. Model protein albumin has been successfully grafted onto the colloidal particles, indicating the reactivity of the carboxyl groups at the PEG free ends. This reactive polyurethane can be used to graft various biomolecules for improving PUs＇ biofunctionality.