模拟研究石墨烯/生物基尼龙复合材料的界面热阻

生物基尼龙(PA56)源于天然产物,具有优良的环保性能和广阔应用前景,有望替代传统的石油基尼龙材料.为了开发基于PA56的导热材料,利用分子动力学模拟研究方法探索了石墨烯/PA56复合材料界面热阻的影响因素.首先,利用实验测试商用PA56样品的玻璃化转变温度(Tg)和导热系数(Tc),验证了PA56模型的模拟参数.接着,通过设计和比较不同表面改性状态对石墨烯/PA56复合材料的界面热阻的影响规律,最后,为了降低界面改性的难度,设计了一种新型的二嵌段共聚物作为石墨烯/PA56复合体系的界面改性剂,研究了界面改性剂的结构对界面热阻的影响规律.研究结果对于实验研究制备生物基尼龙导热复合材料具有重要的参考价值.

Simulation Study on the Interface Thermal Resistance of Graphene/Bio-nylon Composites

Bio-based nylon(PA56)is derived from natural products,which is expected to replace other synthetic nylon products.In order to prepare thermal conductive composites materials based on PA56,molecular dynamics simulation technology is used to explore the interface thermal resistance of graphene/PA56 composite materials.Firstly,the model and simulation parameters for simulated PA56 are testified by comparing physical properties,such as density,temperature of glass transition and thermal conductivity from simulation with those from experiment.There is a good accordance between simulation data and experimental data.And then,the simulated composites of graphene/PA56 is constructed.Various surface modification technologies onto graphene to depress interface thermal resistance between graphene and PA56 matrix are checked in detail.Typically,in cases surface grafted chains onto graphene those may form hydrogen bond with PA56 segments,are more effective to depress interface thermal resistance in the composites than other technologies.Experimentally surface grafting polymer chains onto graphene are expensive and inefficient,compared with that of chemical groups,though.To make a commercially viable surface modification technique,a diblock copolymer PA4-b-PA56 is theoretically designed as macromolecular interfacial modifiers.In the composites,the PA4 segments of diblock copolymer form hydrogen bonds with chemical groups onto modified graphene,and PA56 segments readily mix with matrix polymer chains.As a result,interface thermal resistance between graphene and PA56 matrix are found to be effectively depressed by such macromolecular interfacial modifiers.Such methodology opens a new routine to improve thermal transition among composites.Simulation exploration may help experimentally fabricate thermal conductive graphene/PA56 materials.