线性聚合物链的m级相互作用近似

mth-Order Interaction Approximation for Linear Polymer Chains

导出了线性聚合物链ｍ级相互作用近似统计权重矩阵的递推公式，它满足构象统计的矩阵代数法所要求的连接条件。按作为四元组转动的Ｃ－Ｃ键旋转角的函数计算了正庚烷的构象能。研究了聚乙烯（ＰＥ）链由相隔六键的原子间所施加的四级相互作用对均方末端距和均方回转半径的特征比的影响，结果表明考虑四级相互作用后，ＰＥ链的特征比要比三级相互作用近似的小。

The recurrence formula, which satisfies the necessary linking condition of the matrix algebra method for conformation statistics, of the statistical weight matrices of the mth-order interaction approximation for linear polymer chains is derived. The conformational energy of n-heptane is calculated as a function of the C-C bond rotation angles with a tetradic rotation. The effect of the fourth-order interaction, imposed by the atoms separated by six bonds, of polyethylene(PE) chain on the characteristic ratios of mean-square end-to-end distance and mean-square radius of gyration < rZ2>/ nl 2 and < s 2>/ nlBZ2 is investigated. Results show that the fourth-order interaction approximation makes these characteristic ratios be less than that of the third-order approximation.