THE MOLECULAR STRUCTURE OF POLYETHYLENE .3. DETERMINATION OF LONG CHAIN BRANCHING
THE MOLECULAR STRUCTURE OF POLYETHYLENE .3. DETERMINATION OF LONG CHAIN BRANCHING
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DOI：
10.1021/ja01120a007
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发表时间：
1953-01-01
影响因子：
15
通讯作者：
BILLMEYER, FW
中科院分区：
文献类型：
--
作者：
BILLMEYER, FW
本文提出了一种定量估算链支化的新方法，并应用于聚乙烯。支化聚合物的光散射分子量和特性粘度与线性但在其他方面相同的样品的计算结果进行比较。该方法仅对长分支敏感。按重量平均计算，一些聚乙烯每个分子有4至34个这样的分支。它们的分子量分布极宽，重均分子量与数均分子量之比常常高达20：1，分馏聚乙烯的实验证实了这些结论。
A new method for the quantitative estimation of chain branching is developed and applied to polyethylenes. The light scattering molecular weight and intrinsic viscosity of a branched polymer are compared with those calculated for a linear but otherwise identical sample. The method is sensitive only to long branches. Some polyethylenes have from 4 to 34 such branches per molecule, on a weight-average basis. Their molecular weight distributions are extremely broad; weight-tonumber average molecular weight ratios as high as 20: 1 are often found. Experiments with fractionated polyethylenes con-firm these conclusions.