Effect of polymer modifier chain length on thermal conductive property of polyamide 6/graphene nanocomposites

The influence of polymer modifier chain length on the thermal conductivity of polyamide 6/graphene (GA) nanocomposites, including through-plane (lambda(z)) and in-plane (lambda(x)) directions were investigated. Here, three chain lengths of double amino-terminated polyethylene glycol (NH2-PEG-NH2) were used to covalently functionalize graphene with graphene content of 5.0 wt%. Results showed that lambda(z) was enhanced with the chain length of NH2-PEG-NH2 increased, but lambda(x) reached a maximum value at a certain chain length of NH2-PEG-NH2. The maximum lambda(z) and lambda(x) of GA are 0.406 W m(-1) K-1 and 9.710 W m(-1) K-1, respectively. This study serves as a foundation for further research on the thermal conductive property of graphene nanocomposites using different chain lengths of polymer modifier to improve the lambda(z) and lambda(x) of the thermal conductive materials. (C) 2015 Elsevier Ltd. All rights reserved.