用量子化学参数预测烯烃聚合物热容变化(英文)

Prediction of the change in the heat capacity for vinyl polymers with quantum chemical descriptors

在B3LYP/6-31G(d)水平上对烯烃聚合物单体进行密度泛函理论计算,得到2个量子化学参数,即分子的等容摩尔热容(C_v)和偶极矩(μ),并用来预测烯烃聚合物在玻璃化转变温度的热容变化(C_(p,change)).从训练集用逐步线性回归方法得到的、物理意义非常明确的结构与性能定量关系模型由测试集进行检验.预测值与实验值的相关系数为0.937.这结果表明由这些量子化学参数所建立的关于性能C_(p,change)的定量关系模型能用于聚合物C_(p,change)值的预测,这也证明了量子化学参数能在聚合物结构与性能定量关系研究中能起重要作用.

By carrying out density functional theory （DFT） calculations for the monomers of vinyl polymers at the B3LYP/6-31（d） level, two quantum chemical descriptors, the heat capacity at constant volume （Cv） and the dipole moment （μ）, were obtained and used to preset the change in heat capacity at the glass transition （Cp. change）. A more physical meaningful quantitative structure-property relationship （QSPR） model obtained from the training set with stepwise multiple linear regression analysis （MLRA） was evaluated externally using the test set. Correlation coefficient between the predicted values and experimental values was 0.937 for Cp, change. The result indicates that the QSPR model constructed using quantum chemical descriptors can be applied to predict the Cp, change of polymers, which is a testimony to the role that quantum chemical descriptors play in studying the QSPR of polymers.