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本文对作者等以前提出的应用溶度函数的简易分级法,和应用董履和函数处理沉淀分级数据作了进一步的简化和考验。用在良溶剂和θ溶剂中测定两个特性粘数值来决定 级分的分布参数,在一般的实验条件下不可能达到所要求的精确度,因此改用分相参数Q=R的近似来决定简易分级法中两个级分的分布参数,实际的计算说明Q的取值可以有相当大的变化范围而对结果的影响不大,这样对简易分级法提供了一个简便的权宜办法。对应用董履和函数计算普通分级法的分级数据时,除第一级分和最后级分外,其他各级分的累积分布均可采用直綫近似,此直綫通过M(I=1/2)=(?)_η,M(I=0)=1/2(?)_η两点,可以简省计算,而对结果的影响极小。本文中对一个聚甲基丙烯酸甲酯试样的两种分级数据进行计算的结果,说明上面两种方法都比习惯应用的Schulz-Dinlinger法计算结果更接近于用沉降速度法测定的分子量分布。
This paper further simplifies and tests the simple classification method applied by the authors, such as the application of solubility function, and the application of Dong Lu and function processing precipitation grading data. Determining the distribution parameters of a fraction by determining the two intrinsic viscosities in a good solvent and a theta solvent will not be able to achieve the required accuracy under normal experimental conditions and is therefore decided by the approximation of the phase separation parameter Q = R Simple grading method in the distribution of the two parameters, the actual calculation shows that the value of Q can have a considerable range of changes with little effect on the results, so simple grading provides a convenient way to make ends meet. When using the classification data of the ordinary classification method and the function to calculate the general classification method, the cumulative distributions of all the other components can be approximated by a straight line except for the first and the last fractions. The straight line passes through M (I = 1/2) = (?) _ η, M (I = 0) = 1/2 (?) _ η two points, can be calculated simply, and the impact on the results is minimal. In this paper, the results of two graded data of a polymethylmethacrylate sample indicate that both of the above methods are closer to the molecular weight distribution determined by the sedimentation rate method than the conventionally used Schulz-Dinlinger method.