^(13)C—NMR方法测定高密度聚乙烯的链结构

Determinetion of Chain Structure of High Density Polyethylene by ^(13)C-NMR Spectra

用^(13)C-NMR 方法测定了高密度聚乙烯(HDPF)的支化度和链结构。用 Lindeman-Adams(LA)参数计算了化学位移,参考计算值,对实测到的峰进行了归属。利用最小二乘法和观察平均法对支链大于1/10000个碳的各类支化链的长度、含量作了定量计算。

The chain structurel and existence of various branches of high density polyethylenewere determined by ^(13)C-NMR.The^(13)C chemical shifts of observed peaks of all kinds of brancheswere compared with those of the peaks calculated by Lindeman-Adams Additivity Rule.Theconcentration of all branches was found quantitatively by a least-square and observation averagemethods.The rusults obtained from two methods were discussed in detail,which shows that therelatively precise quantitative rusults can be obtained for the number of carbon atoms of branchesgreater than one ten thousandth of carbon atoms.