化学学报 ›› 2001, Vol. 59 ›› Issue (10): 1809-1812. 上一篇    下一篇

研究论文

新型两亲性生物降解聚酯单体的合成及其开环聚合

杨纪元;余坚;李梅;潘怀忠;顾忠伟;曹维孝;冯新德   

  1. 北京大学化学与分子工程学院;北京大学高分子科学与工程系;国家计划生育委 员会科研所医用高分子材料研究中心
  • 发布日期:2001-10-15

A novel biodegradable polyester with hydrophilic pendant group — synthesis and ring-opening polymerization of 3-benzyloxymethyl-1,4- dioxane-2,5-dione

Yang Jiyuan;Yu Jian;Li Mei;Pan Huaizhong;Gu Zhongwei;Cao Weixiao;Feng Xinde   

  • Published:2001-10-15

以3-氯代丙二醇为起始原料,通过3-苄氧基甘油酸(3-O-BGA)为中间体,首次合成了作为一种新型聚羟基酸前体的,具有苄氧保护基的六元环状二交酯—3-苄氧次甲基-1,4-二氧六环-2,5-二酮(3-BMG)。该单体具有通常交酯的聚合特性,很容易以辛酸亚锡为催化剂,在140℃下开环聚合得到高分子量的聚合物。在双金属(Al/Zn)烷氧化合物引发体系下也能够进行开环聚合。所得聚合物在Pd/C催化下氢解,可以定量地去除苄基保护基,从而得到侧链带有羟基的新型功能性可生物降解聚酯。DSC实验结果显示脱保护的聚合物的玻璃化转化温度下降,并在120℃附近出现熔点。通过吸水率与动态接触角的测定,脱保护后聚合物的亲水性显著提高,明显高于传统的聚酯。

关键词: 聚酯, 甘油酸, 降解, 开环聚合, 氯代丙二醇, 氢解, 亲水性

The synthesis of a new cyclic ester, 3-benzyloxymethyl- 1,4-dioxane- 2,5-dione(3-BMG), was described, which is a precursor of a novel poly( α-hydroxy acid). As an important intermediate, 3-benzyloxy-glyceric acid (3-O-BGA) was obtined and first isolated as white needle crystal using 3-chloro-propandiol as starting material. Polymerization of 3- BMG was carried out in bulk at 140℃ with stannous 2-ethyl hexanoate [Sn(Oct)2] as catalyst. High molecular weight ofpolymer obtained indicates that the polymerization behavior of 3-BMG is similar to that of common lactides or lactones. 3-BMG can also be polymerized by the bimetallic (Al/Zn) alkoxide initiator. The resulting polymer undergoes hydrogenolysis at atmospheric pressure in the presence of a palladium on charcoal and the pendant benzyl group was removed completely. The glass transition temperature (Tg) of the polymer decreases after deprotection. And the deprotective polymer has melting temperature around 120℃. The data of water absorbing and contact angle determinations suggest that the hydrophility of the polymer was improved obviously after deprotection.

Key words: POLYESTER, DEGRADATION, RING OPEN POLYMERIZATION, HYDROGENOLYSIS, HYDROPHILICITY

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