论文部分内容阅读
基于改进的构象-构型统计方法,推导了计算均方电偶极矩和均方回转半径的通用公式,应用于研究侧基的结构和极性对聚乙烯醇(PVA),聚乙烯基甲基醚(PVME)和聚醋酸乙烯酯(PVAc)等链物理性质的影响.计算得到其全同链均方电偶极矩特征比分别为2.51、2.15和1.39,间同链温度系数差异达到5.68×10-3K-1,并且均方电偶极矩与侧基极性的方向和链构型、均方回转半径与侧基尺寸和柔性有明显相关性.通过比较特征比对构象能的微分值,发现PVA、PVAc和PVME侧基的相互作用能对特征比的影响比聚乙烯吡硌烷酮的影响更大,如PVME微分值可达到-81.2×10-2mol/J.通过对照特性黏数,观察到聚丙烯酸甲酯的值比PVAc的值更为多变.
Based on the improved conformation-configuration statistics, a general formula for calculating mean square dipole moment and mean square radius of gyration was deduced and applied to study the effect of structure and polarity of side groups on the properties of polyvinyl alcohol (PVA), polyvinyl (PVME) and poly (vinyl acetate) (PVAc). The calculated characteristic ratios of the equipotential chain mean square dipole moments were 2.51, 2.15 and 1.39, respectively, and the differences of the temperature coefficient between syndroms reached 5.68 × 10-3K-1, and the direction and chain configuration of the mean square dipole moment and the side polarities, the mean square gyration radius has a significant correlation with the size and flexibility of the side groups. By comparing the characteristic differentials Value, it was found that the interaction of PVA, PVAc and PVME side groups on the characteristic ratio than polyvinylpyrrolidone greater impact, such as PVME differential value can reach -81.2 × 10-2mol / J. Through the control of intrinsic viscosity The value of poly (methyl acrylate) was observed to be more variable than that of PVAc.