聚乳酸中间体——丙交酯制备工艺

Preparation of Polylactic Acid Intermediate Lactide

研究了间接法合成聚乳酸用的中间体丙交酯的制备工艺。以工业D,L-乳酸(lacticacid)为原料,丙交酯粗产物的收率为考查指标,通过正交实验得到了最佳制备工艺条件为:以4%(v/v)的辛酸亚锡为催化剂,脱水温度为180℃,解聚温度为285℃,得到粗产物收率为72.4%。粗品丙交酯1次重结晶后收率为59.3%,熔点为95.0～96.2℃;5次重结晶后总收率为50.7%,熔点为125.2～126.5℃。同时采用FTIR与1HNMR对产物进行了结构表征。

Preparation of lactide was carried out using indirect method in this paper. Lactide was syntheslzed trom industrial monomer D,L-lactic acid as raw material. The optimal conditions for synthesis of lactide were investigated by the orthogonal experiments. Results indicated that under the optimal conditions such as using v （Sn（Oct）2）/v （Lactic acid）=0.4：1 Sn（Oct）2 as catalyst, dehydration temperature 180℃ and decomposing temperature 285℃, the yield of lactide reach 72.4%, and the yield of lactide reached 59.3% after the first recrystalization, and its melting point ranged from 95.0℃ to 96.2℃. The yield of lactide reached to 50.7% and its melting point ranged from 125.2℃ to 126.5℃ after the fifth recrystallization. FTIR and ^H NMR were used to characterizing the products.