羟基乙酸

The preparation of polymer is required for high purity of glycolic acid, if not, low-weight polymer is obtained, therefore, high purity glycolic acid is scarce in the market. So, the research for the synthesis of glycolic acid is essential. In domestic and overseas, there are many methods for preparation of glycolic acid, including glycin oxidation, cyanogenesis, aldehyde oxidation, coupling of maldehyde and methyl formate, oxalic acid electrolysis, chloroactic acid hydrolysis and so on.

制备羟基乙酸的聚合物时，对羟基乙酸单体的纯度要求较高，否则得到的聚合物分子量较低，导致高纯度羟基乙酸的需求量逐年增长，目前在国内，高纯度的羟基乙酸还没有形成工业化规模生产，对羟基乙酸的合成进行研究是非常有意义的。

The reparing high molecular material was divided into absorbable and unabsorbable material,the former included polyglycolic-acid and polyglaction,the later consists of polypropylene polyester and expanded polytetrafluoroethylene.

人工高分子修补材料主要有可吸收和不可吸收两大类，前者有聚羟基乙酸和聚乳酸羟基乙酸两种，后者有聚丙烯网、膨体聚四氟乙烯片及聚酯纤维网。

It showed that the yield of hydroxyacetic acid reached above 99.5%, the extracting efficiency was over 97%,and the product with purity of more than 96% was obtained. Extractant and solvent also can be reused.

实验结果表明：羟基乙酸合成的反应产率达99.5%以上，羟基乙酸萃取率达97%以上，最终收率达96%，萃取剂与溶剂均可循环使用。

Hydroxyacetic acid was synthesized by glycolonitrile in the presence of H2SO4 , and it was separated by applying extraction based on chemical complexation and solvent method.

以羟基乙腈为原料，在酸性条件下水解合成羟基乙酸，并采用络合萃取法和溶剂溶解法分离羟基乙酸。

The amount of hydroxyacetic acid , equal to that of sodium chloride, produced from chloroacetice acid hydrolysis is determined by adopting Moore method and there fore the ratio of transformation of chloroacetice acid hydrolyzed can be calculated.

氯乙酸水解生产羟基乙酸的工艺过程中产生等物质量的氯化钠，采用莫尔法测定氯乙酸水解的产物氯化钠，并计算氯乙酸的水解转化率，从而选择和控制水解反应的条件。

The review highlights the technical developments in the identification,quantification and separation of α-hydroxyacetic acid,especially solvent extraction and synergistic extraction.

文章比较了各种羟基乙酸定性及定量分析方法，综述了羟基乙酸分离方法，特别是溶剂萃取和协同萃取效应。最后，分析了羟基乙酸的开发前景。

The advantages of α-hydroxyacetic acid biosynthesis over traditional chemical conversion are wide range of reaction condition,high conversion ratio and green process.

化学法生产羟基乙酸存在原料消耗大、产品收率低、环境污染严重等缺点；生物法合成羟基乙酸条件温和、底物转化率高，为绿色合成羟基乙酸提供强有力的技术支持。

Those biodegradable materials finally form into CO2 and H2O via culture of tricarboxylic acid cycle, which can be excreted from lung, kidney, and skin. Hydroxyacetic acid is a metabolic product of amino acids. Therefore, velocity of bioldegradable materials can be controlled in vivo. The recent contraception focuses on discover a sustained release system of biodegradable materials.

生物可降解材料包括聚乳酸、聚ε-己内酯、乳酸-羟基乙酸共聚物等，这些材料有很好的生物相容性，植入体内后可经生物降解成乳酸单体，经三羧酸循环后最终成为CO2和H2O，经肺、肾、皮肤排泄，羟基乙酸也是机体氨基酸代谢产物，而且生物可将解材料在体内降解速度是可控的，用生物降解聚合物作为药物载体的缓释避孕系统是目前材料学以及避孕节育研究的一大重点。

Moreover, the suggestions on development of domestic glycollic acid in the future are put forward also.

最后对羟基乙酸在国内外的生产现状进行分析，并对国内羟基乙酸今后的发展提出几点建议。

And the application of glycollic acid in the fields of chemical cleaning, auxiliaries and materials were introduced in detail.

概述了羟基乙酸几种主要工业合成方法的工艺条件及存在的主要问题，即氯乙酸水解法、氰化法、甲醛羰基化法和一氯乙酸钾水解法。

The objective is to subjugate and discourage the people, because that allows the elite to continue to rule unopposed.

其目的是压制和打击人民的积极性，因为这可以让实权派继续统治不会沦为反对派。

GOD,this is the second time you vanquished me!

天啊，这是第二次你打败了我！