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基于旋转异构态模型和生成矩阵统计方法,推导了极性取代基高分子链均方回转半径和均方偶极矩改进的计算公式,应用于研究聚卤乙烯链构象和构型依赖的性质,包括均方回转半径和偶极矩特征比与构象能、链规整程度和温度的关系.发现构型规整的聚卤乙烯链特征比、温度系数和构象能依赖性质均呈现较大的差异,尤其是间同和全同构型链.如聚卤乙烯间同链偶极矩特征比随主要相互作用Eη变化比例在-0.62~0.05(J/mol)-1之间.相反,构型不规整的聚卤乙烯链的无扰尺寸则比较接近.聚氟乙烯、聚氯乙烯和聚溴乙烯无规链均方偶极矩特征比分别为0.80、0.69和0.59,均方偶极矩温度系数为-0.07×10-3~-0.53×10-3 K-1,与实验结果符合.研究结果表明聚卤乙烯单体性质和构型对其链柔性和链极性的影响是显著的.
Based on the rotational isomerism model and the generating matrix statistical method, the formulas for calculating the mean square radius of gyration and the mean square dipole moment of the polar substituent polymer chains are deduced and applied to study the conformational and configurational dependence of the polyvinyl halide chains , Including the relationship between the mean square radius of gyration and dipole moment characteristic ratio and the conformational energy, chain regularity and temperature.It is found that the structural characteristics of the regular poly (vinyl halide) chains have different characteristics, temperature coefficients and conformational dependence properties, Especially the syndiotactic and isomorphic chains, such as the characteristic ratio of dipole moments in the same chain of poly (vinyl halide) with the main interaction Eη change between -0.62 ~ 0.05 (J / mol) -1. Conversely, the configuration is irregular Of the poly (vinyl halide) chains are close to each other.The characteristic ratios of random chain mean square dipole moment of poly (vinyl fluoride), polyvinyl chloride (PVC) and poly (vinyl bromide) are 0.80, 0.69 and 0.59, respectively, and the temperature coefficients of mean square dipole moment are -0.07 × 10-3 ~ -0.53 × 10-3 K-1, which is in good agreement with the experimental results.The results show that the properties and configuration of poly (vinyl halide) monomer have significant influence on the chain flexibility and chain polarity.