【摘要】 以营养丰富的厨房垃圾为原料,通过接种乳酸菌发酵,得到了乳酸含量为31.47g?L?1的厨房垃圾发酵液;用电渗析法从厨房垃圾发酵液中提取乳酸,将电渗析分离液经减压脱水浓缩至乳酸含量为70%~80%(wt),作为合成丙交酯的原料。选用氧化锌作为解聚剂,分析纯D,L-乳酸作为原料通过正交设计实验确定了生成丙交酯的最佳条件为:预聚温度150℃,预聚时间3h,解聚剂用量为1.0%(wt),解聚温度220℃;在此条件下,以厨房垃圾发酵液提取的乳酸为原料合成丙交酯,其产率为60%。该丙交酯经熔点测定、红外光谱和核磁共振分析的结果表明:用厨房垃圾的乳酸发酵液合成的丙交酯为D,L-丙交酯。本工艺不但可降低丙交酯的生产成本,而且解决了厨房垃圾的环境污染问题。更多还原

【Abstract】 The kitchen garbage was sterilized and inoculated with lactic acid bacteria, and after 3~4 days of fermentation the lactic acid in the fermentation broth (containing 31.47 g?L?1 lactic acid) was recovered by electrodialysis and condensed to a high concentration (70%~80% (wt) of lactic acid) which will be used latterly as the raw material for synthesizing lactide. The orthogonal-design experiments were conducted to find out the suitable reaction conditions for synthesizing lactide. In these experiments, the zinc oxide was used as depolymerization agent and the analytically pure D,L-lactic acid as reagent to produce lactide. The suitable conditions found are as follows; the prepolymerization is taken at 150°C for 3h, 1%(wt) depolymerization agent is used and the depolymerization temperature is 220°C. Under above reaction conditions, when the electrodialyzed and concentrated fermentation broth from kitchen garbage is used instead of the pure lactic acid as reagent, the yield ratio of lactide could be 60%. The results from IR spectrum, 1HNMR spectrum and melting point tests show that the product is D, L-lactide. This technology can not only reduce the cost of producing lactide, but also solve the pollution problems from kitchen garbage.更多还原