【摘要】 通过线性聚二氯膦腈(PDCP)的大分子亲核取代反应,合成了两个新的具有不同比例4-乙氧羰苯氧基、乙氧基吡咯烷酮和甲氧基乙氧基乙氧基侧基的聚膦腈,并用31P NMR、1H NMR、IR和元素分析表征了它们的结构。分别用DSC和蒸汽压渗透法(VPO)测定了它们的玻璃化转变温度Tg和数均分子量。两个新聚膦腈的体外降解实验和降解产物的定性分析结果表明,亲脂性的乙氧羰苯氧基含量越高,聚膦腈的降解速度越慢。两个聚膦腈在不同缓冲溶液中的降解从快到慢的次序为pH 5.0>pH 7.4>pH 8.0。它们的降解是侧链首先断裂,然后才是骨架的裂解。更多还原

【Abstract】 Two new biodegradable polyphosphazenes with N-ethoxypyrrolidone,4-ethyl oxybenzoate and methoxyethoxyethoxy side groups were synthesized via the route of macromolecular substitution.Their structures were confirmed by 31P NMR,1H NMR,IR,DSC and elemental analysis.Their molecular weights were determined by vapor pressure osmometry(VPO).In vitro degradation properties and degradation products of the polymers were investigated.The results showed that the degradation of the polymers were dependent on pH of the buffer solution.The hydrolysis rate of the polymers decreased in the order of pH5.0 > pH7.4 > pH8.0 of the buffer solution.The higher content of 4-ethyl oxybenzoate in the polymer gave rise to slower degradation.The degradation of the polymers involved a hydrolytic cleavage of N-ethoxypyrrolidone and 4-ethyl oxybenzoate from the chain followed by the degradation of the phosphorus-nitrogen backbone to form phosphate and ammonia.更多还原