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本文用质子和硅-29核磁共振方法直接测定α,ω一二乙氧基聚二甲基硅氧烷端基的含量,并由此计算其平均聚合度。由动力粘度对聚合度作图,获得粘度与数均分子量的关系。发现较低分子量的聚硅氧烷[(?)(聚合度)<56]粘度与数均分子量成简单的线性关系。用数理统计方法对数据进行处理,求得经验公式:(?)=0.76η_(25℃(cp))+5.6。高分子量聚硅氧烷粘度与分子量的关系则呈双对数绂性关系。实验结果表明:用~1H和~(29)SiNMR两种方法获得的数据吻合得很好。而~1HNMR方法比~(29)SiNMR方法测定范围更宽,更简便。
In this paper, proton and silicon 29 nuclear magnetic resonance method for direct determination of α, ω a diethoxy polydimethylsiloxane terminal content, and calculate the average degree of polymerization. From the dynamic viscosity of the degree of polymerization mapping, viscosity and number average molecular weight relationship. It was found that lower molecular weight polysiloxanes ((?) (Degree of polymerization) <56) had a simple linear relationship with the number average molecular weight. Using mathematical statistics to process the data, the empirical formula is obtained: (?) = 0.76η_ (25 ℃ (cp)) + 5.6. The relationship between viscosity and molecular weight of high molecular weight polysiloxane showed a double logarithmic relationship. The experimental results show that the data obtained by ~ 1H and ~ (29) SiNMR agree well with each other. However, the ~ 1HNMR method is broader and easier than the ~ (29) SiNMR method.