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首页> 外文期刊>Journal of Applied Polymer Science >Synthesis of amphiphilic (meth)acrylates with oligo(ethylene glycol) and (or) oligo(propylene glycol) blocks by the esterification of (meth)acrylic acid
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Synthesis of amphiphilic (meth)acrylates with oligo(ethylene glycol) and (or) oligo(propylene glycol) blocks by the esterification of (meth)acrylic acid

机译：用（甲基）丙烯酸的酯化合成寡核苷酸（甲基）丙烯酸（甲基）丙烯酸（或）寡核苷酸（或丙二醇）嵌段（甲基）丙烯酸

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Thermoresponsive PEG-based (PEG stands polyethylene glycol) polymers are unique for use in medicine because of their low toxicity, good biocompatibility and biodegradability, but usually more hydrophobic and more toxic comonomers are used to adjust lower critical solution temperature (LCST). A convenient way to overcome this problem and to finely tune LCST is to use alkoxy oligo(ethylene glycol)- or alkoxy oligo(propylene glycol) (meth)acrylates as starting comonomers. Here we report on the conditions for the simple and affordable synthesis of methoxy oligo(propylene glycol) (meth)acrylate- and methoxy oligo(propylene glycol)-block-oligo(ethylene glycol) (meth)acrylate-based macromonomers with high yields (80%-98.7%) by the acid-catalyzed esterification of (meth)acrylic acid with alkoxy oligo(alkylene glycols) containing oligo(ethylene glycol) (OEG) and/or oligo(propylene glycol) (OPG) blocks. p-Toluene sulphonic acid (pTSA), alkyl(C-12-C-14)benzene sulfonic acid (ABSA) and H2SO4 were used as catalysts. It has been shown that pTSA and ABSA are practically the same in catalytic activity and are superior to sulfuric acid. The reaction orders with respect to catalyst was found to be close to 1 in all cases. It has been shown that the reaction is actually insensitive to the lengths of OEG and OPG blocks, as well as to the structure of the terminal alkyl group, while the esterification of acrylic acid (AA) proceeds much faster compared to methacrylic acid (MAA) one under the same conditions. The influence of temperature on the equilibrium conversions of alcohols was determined, which were found to be 89%-93% for the esterification of AA and 61%-86% for MAA in the temperature range of 60-120 degrees C. A further increase in conversion was achieved by introducing an azeotropic agent (toluene), its optimal concentration was found to be 10%-15%.
机译：PEG基热响应聚合物（PEG代表聚乙二醇）因其低毒性、良好的生物相容性和生物降解性而在医学上具有独特的用途，但通常使用更疏水、更有毒的共聚单体来调节较低的临界溶液温度（LCST）。克服这个问题和微调LCST的一个方便方法是使用烷氧基低聚（乙二醇）或烷氧基低聚（丙二醇）（甲基）丙烯酸酯作为起始共聚单体。在这里，我们报道了通过酸催化（甲基）丙烯酸与含有低聚（乙二醇）和/或低聚（亚烷基二醇）的烷氧基低聚物（亚烷基二醇）的酸催化酯化反应，以高收率（80%-98.7%）合成甲氧基低聚（丙二醇）（甲基）丙烯酸酯-和甲氧基低聚（丙二醇）-嵌段低聚（乙二醇）（甲基）丙烯酸酯基大单体的条件低聚（丙二醇）（OPG）块。以对甲苯磺酸（pTSA）、烷基（C-12-C-14）、苯磺酸（ABSA）和硫酸为催化剂。结果表明，pTSA和ABSA的催化活性基本相同，且优于硫酸。在所有情况下，催化剂的反应级数均接近1。研究表明，该反应实际上对OEG和OPG嵌段的长度以及末端烷基的结构不敏感，而在相同条件下，丙烯酸（AA）的酯化反应比甲基丙烯酸（MAA）的酯化反应进行得快得多。测定了温度对醇平衡转化率的影响，发现在60-120℃的温度范围内，AA的酯化率为89%-93%，MAA的酯化率为61%-86%。通过引入共沸剂（甲苯）进一步提高转化率，发现其最佳浓度为10%-15%。

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