丙三醇与1,6-己二醇混合物降温凝固过程的分子动力学模拟

Molecular dynamics simulation of solidification process for mixtures of glycerol and 1,6-hexanediol

利用分子动力学方法对3种不同摩尔比的丙三醇与1,6-己二醇混合物进行降温计算。分别采用自扩散系数和比体积方法得到的玻璃化转变温度与实验结果都符合较好,混合物中的丙三醇与1,6-己二醇的自扩散系数均小于单质时的自扩散系数,丙三醇与1,6-己二醇的羟基比其单质状态的羟基径向分布函数中第一峰值均变大,且随着温度的降低,回转半径变短,较小的键长出现的概率增多,键角变化较小。

The solidification process of mixtures of glycerol and 1,6-hexanediol with three mole ratios are carried out using molecular dynamics method.Self-diffusion coefficient and the specific volume method are used to calculate glass transition temperature separately,and the results are in good agreement with the experimental data.The self-diffusion coefficients of glycerol and 1,6-hexanediol hydroxy in mixtures are less than that of glycerol and 1,6-hexanediol hydroxyl.The first peak values of radial distribution function of glycerol and 1,6-hexanediol hydroxy in the mixture are higher than that of pure glycerol or pure 1,6-hexanediol hydroxy.As the temperature decreases,the radius of gyration is shorter,smaller bond lengths appear more,and bond angles change little.