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机构地区:[1]哈尔滨工业大学市政环境工程学院绿色化学与技术研究中心,黑龙江哈尔滨150090
出 处:《过程工程学报》2007年第2期306-309,共4页The Chinese Journal of Process Engineering
基 金:哈尔滨市科技攻关基金(编号:2005AA4CS112)
摘 要:考察了两种绿色无毒溶剂乙酸乙酯和乙醇在D,L-丙交酯提纯过程中的使用情况. 以熔点为指标表征重结晶后D,L-丙交酯的纯度,考察了重结晶温度、时间及D,L-丙交酯/溶剂比例对D,L-丙交酯重结晶收率的影响. 结果表明,在不同重结晶温度、时间及溶剂用量下,两种溶剂提纯3次后的D,L-丙交酯熔点均能达到聚合的要求. 使用两种溶剂提纯的经济性对比表明,乙醇较适宜作为D,L-丙交酯扩大生产中的提纯溶剂,其最佳的提纯条件为温度4℃或更低,重结晶时间在1 h以上,乙醇使用量为2.5 mL/g. 在此条件下,提纯3次后D,L-丙交酯的收率约为63%. 对重结晶所得物质进行了元素分析、FT-IR分析及1H-NMR分析,结果表明所得产物为环状D,L-丙交酯结构.Ethyl acetate and ethanol as two kinds of nontoxic solvent were studied in the process of purification of D,L-lactide. The effects of recrystallization temperature, time span and ratio of D,L-lactide to solvent on the yield of D,L-lactide were investigated, with the melting point as the designation of D,L-lactide purity. The results show that under different temperatures, different time spans and different ratios of D,L-lactide to solvent, the melting point of D,L-lactide purified three times with either solvent can meet the request for polymerization. The economic comparison of these two solvents indicates that ethanol is more suitable to be the solvent in the purification of D,L-lactide and the optimal conditions are obtained as recrystallization temperature 4 ℃ or lower, time span more than 1 h and dosage of ethanol 2.5 mL/g. The yield of D,L-lactide after 3 times purification with the optimal conditions is 63%. The product was characterized by elemental analysis, FT-IR and ^1H-NMR, and the results demonstrated that it fit the cycle-structure of D,L-lactide.
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