为了探索在以羧基单体为主要功能单体的乳液聚合中乳液的羧基分布,基于不同存在形式的羧酸(包括:表面结合酸,包埋酸和自由酸)具有不同的电离常数这一原理,采用电导滴定法测定了不同聚合物乳液的羧基分布.分别改变羧基单体的类型和用量、聚合工艺、滴加策略等实验条件,对不同条件下乳液的羧基分布情况进行了研究.结果表明,电导滴定法可以准确地测定聚合乳液的羧基分布,同时,该方法具有简单方便、准确可靠、适用性较强等优点.%In order to investigate the distribution of carboxylic group in emulsion polymerizations which use carboxylic monomers as main functional monomers, according to the fact that carboxylic group in different existing forms (including carboxylic group on the surface of particle, embedded in particle and in aqueous phase) has different ionization constants, conductometric titration method was used to determine carboxylic group distribution in different polymer emulsions. The effects of the amount and types of functional monomers, polymerization technologies and the dropwise manners of monomers on the carboxylic group distribution of emulsions were studied. The determination process of carboxylic group distribution and the computing method of carboxylic group in different forms were illustrated in detail. The results show that the conductometric titration method can determine the carboxylic group distribution accurately. This method is simple and convenient, reliable and has a broad application.
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