In situ synthesis of thermoplastic polyurethane/graphene nanoplatelets conductive composite by ball milling

Thermoplastic polyurethane/graphene nanoplatelets conductive composite was in situ synthesised by ball milling at room temperature, using polytetramethylene glycol as soft segment, 4-methyl-m-phenylene diisocyanate as hard segment, 1,4-butanediol as chain-extending agents, graphene nanoplatelets as conductive filler. Carbon black was used as contrast conductive filler, stir was used as contrast method. The mechanisms and influence of different ball milling time to exfoliate layered graphene nanoplatelets and compound with thermoplastic polyurethane resin were studied. The morphology, electrical, mechanical and thermal properties of thermoplastic polyurethane/graphene nanoplatelets composite were investigated too. It showed that ball milling was an effective method to prepare thermoplastic polyurethane/graphene nanoplatelets conductive composite of low loading level by avoiding aggregation of graphene nanoplatelets. The percolation threshold effect of thermoplastic polyurethane/graphene nanoplatelets composite by ball milling 6 h occurred at the content around 2 wt% of the graphene nanoplatelets, which was much lower than 6 wt% of that prepared by stir. Besides, thermoplastic polyurethane/graphene nanoplatelets composite showed much better conductive and mechanical properties than thermoplastic polyurethane/carbon black composite.