尼龙6/季铵盐/蒙脱土复合材料介观-宏观模拟

Mesoscopic and Macroscopic Scales Simulations on Nylon-6 /Quaternary Ammonium Salt /Montmorillonite Nanocomposites

采用耗散粒子动力学(DPD)和有限元分析方法(FEM)对十六烷基三甲基氯化铵(CTAC)、十六烷基三甲基溴化铵(CTAB)和十八烷基三甲基氯化铵(OTAC)改性蒙脱土(MMT)的尼龙6(PA6)/季铵盐(Quat)/MMT纳米复合材料进行了研究。通过将分子动力学(MD)模拟得到的非键相互作用能转化为介观DPD模拟中的各珠子间的相互作用参数,用DPD模拟方法研究了共混物的介观形貌。通过将DPD模拟得到的介观形貌转化为宏观模拟中有限元分析(FEM)的输入结构,采用FEM方法预测了共混物的力学性能。FEM分析结果表明,共混物为各向异性材料,在zz方向的拉伸模量(E)与文献值基本一致,且比垂直于zz方向(xx和yy方向)的低得多。

The relationship between structures and properties of nylon-6( PA6) /quaternary ammonium salt( Quat)/montmorillonite( MMT) nanocomposites systems was investigated by the dissipative particle dynamics( DPD) simulation and the finite element( FEM) method. MMT were organic modified by cetyltrimethylammonium chloride( CTAC),cetyltrimethylammonium bromide( CTAB) and octadearyl dimethyl ammonium chloride( OTAC) respectively. DPD was adopted as mesoscopic simulation technique,and the interaction parameters of the mesoscopic model were estimated by mapping the corresponding nonbonded interaction energy values obtained from molecular dynamics( MD) simulations.The output of DPD served as the input morphology for FEM simulations,which were used to predict mechanical properties of nanocomposites based on the simulated morphology. The FEM simulation results show that the blend represents an anisotropic behavior,the modulus along zz direction shows good agreement with the reference value and is lower than that perpendicular to zz direction( along xx and yy direction).