CAJ | 학술논문

为研究二异氰酸酯类型、温度、硝化甘油（ NG）含量等因素对NG在聚氨酯弹性体内扩散性能的影响，用分子动力学方法，在COMPASS力场下对NG和聚氨酯弹性体混合体系进行了模拟。构建NG与不同聚氨酯弹性体的混合体系模型，并进行结构优化，先后进行恒温恒压系综（ NPT）和恒温恒容系综（ NVT）的分子动力学模拟，得到NG在混合体系中的均方位移，通过爱因斯坦方程计算得到其扩散系数。结果表明：NG在聚氨酯弹性体内扩散系数的数量级为10-8 cm2· s-1，与实验数据一致；扩散系数随聚氨酯弹性体链的柔顺性增加而上升；随温度的不断升高，扩散系数先缓慢上升，当超过308 K后，扩散系数急剧增加。随NG含量的不断升高，扩散系数先缓慢下降，当超过14％后，扩散系数急剧下降。
위연구이이청산지류형、온도、초화감유（ NG）함량등인소대NG재취안지탄성체내확산성능적영향，용분자동역학방법，재COMPASS력장하대NG화취안지탄성체혼합체계진행료모의。구건NG여불동취안지탄성체적혼합체계모형，병진행결구우화，선후진행항온항압계종（ NPT）화항온항용계종（ NVT）적분자동역학모의，득도NG재혼합체계중적균방위이，통과애인사탄방정계산득도기확산계수。결과표명：NG재취안지탄성체내확산계수적수량급위10-8 cm2· s-1，여실험수거일치；확산계수수취안지탄성체련적유순성증가이상승；수온도적불단승고，확산계수선완만상승，당초과308 K후，확산계수급극증가。수NG함량적불단승고，확산계수선완만하강，당초과14％후，확산계수급극하강。
The influences of temperature, content of nitroglycerin( NG) , structure of diisocyanate on the diffusion behaviors of NG in elastomeric polyurethane were investigated by the molecular dynamics method with COMPASS ( Condensed-phase Optimized Molecular Potentials for Atomistic Simulation Studies) force field.The mixed models of NG and different elastomeric polyurethane were also constructed and optimized.The mean square displacement of NG in mixtures was obtained by the molecular dynamics simulation of NPT( constant-temperature, constant-pressure ensemble) and NVT( constant-temperature, constant-volume ensem-ble) .The diffusion coefficients were obtained by the Einstein equation.The results show that the order of magnitude of diffusion coefficients of NG in elastomeric polyurethane reaches 10 -8 cm2 · s-1 , which is in agreement with experiment.The diffusion coefficients increase with the increasing of chain flexibility, and increase slowly when the temperature belows 308 K and then increase quickly.At meanwhile, the diffusion coefficients decrease slowly at first, and quickly when the content of NG exceeds 14%.