二氧化碳基聚碳酸酯二元醇末端羟基含量的测定  

Terminal Hydroxyl Content Determination of Carbon Dioxide Based Polycarbonate Diols

作　　者：尹静瑶 肖敏 王拴紧 孟跃中 YIN Jing-yao;XIAO Min;WANG Shuan-jin;MENG Yue-zhong(Key Laboratory of Low-carbon Chemistry&Energy Conservation of Guangdong Province,School of Materials Science and Engineering,Sun Yat-sen University,Guangzhou 510006,China)

机构地区：[1]广东省低碳化学与过程节能重点实验室中山大学材料科学与工程学院,广州510006

出　　处：《高分子通报》2023年第6期713-719,共7页Polymer Bulletin

基　　金：国家自然科学基金(22179149)资助项目。

摘　　要：羟值滴定是一种基于羟基的化学特性,通过定量二元醇中的末端羟值从而表征二元醇分子量的化学分析方法。聚氨酯通常是以多元醇和多异氰酸酯为原料通过羟基(—OH)和异氰酸酯基团(—NCO)之间的聚加成反应得到,且—OH与—NCO的比例尤为重要,因此需要准确计算所用二元醇中羟基含量。以环氧类化合物和CO_(2)为原料直接合成的聚碳酸酯型二元醇(PCDL)粘度大且与水互溶性差,因此本文用改进的乙酸酐-甲基咪唑-二甲基甲酰胺滴定方法对市售和自制PCDL进行羟值滴定测试,详细探讨了滴定过程中的各种因素对滴定结果的影响。优化后的羟值滴定方法相比于行业标准方法,减少了样品和试剂用量且酰化反应仅需在45℃水浴20 min完成,节约了测试时间,提高了羟值滴定效率。Hydroxyl value titration is a chemical analysis method that calculates the molecular weight by quantifying the terminal hydroxyl value in the diol based on the chemical nature of the hydroxyl groups.Polyurethanes are usually obtained from polyols and polyisocyanates through a polyaddition reaction between hydroxyl groups(—OH)and isocyanate groups(—NCO),and the ratio between them is particularly important in the process of producing polyurethanes.Therefore,it is necessary to accurately calculate the hydroxyl value of used polyols.Due to the high viscosity and poor water solubility of polycarbonate diol(PCDL)synthesized from epoxides and CO_(2) directly,we used an improved hydroxyl value titration strategy(acetic anhydride-methylimidazole-dimethylformamide method)to measure the hydroxyl value of commmercial and synthesized PCDL.The effects of various factors in the process of titration on hydroxyl value were discussed in detail.Compared with the industrial standard method,this optimized method can reduce the amount of samples and chemical reagents,moreover,the acylation reaction can be completed in a 45℃water bath for only 20min,which saved the test time and thus improved the efficiency.

关 键 词：二氧化碳基聚合物 聚碳酸酯二元醇 羟值滴定 乙酸酐-甲基咪唑-二甲基甲酰胺法 

分 类 号：O655.2[理学—分析化学]