Preparation And Properties Of Carbon Nanotubes Reinforced Composites

Carbon nanotube(CNT)is considered as an ideal reinforcement for excellent mechanical,electrical and thermal properties.However,it is often difficult to uniformly disperse high-content CNTs into the matrix while the orientation of CNTs is not guaranteed,as a result,the performance of the composite material is much lower than expected.It is an effective method to prepare high performance CNT composites by using CNT macroscopic materials such as CNT films as reinforcement materials.For example,high performance CNT/polymer composites were prepared by array spinning,but it is difficult to control the size of the composites and to proceed with continuous preparation due to the limited size of the substrate.In this thesis,CNT/EP composite films were prepared by in-situ deposition of a hollow CNT macroscopic material by CVD method in open atmosphere.Epoxy resin solution penetrated into the CNT tube bundle to achieve the complex of CNT and epoxy resin at the molecular level.A paper tape process and a rotating roller process were adopted to prepare composite films with good mechanical and electrical properties.The CNT content and the collection rate had a great influence on the performance of the composite film.The strength and conductivity of the composite film(CNT content:24.5 wt%)prepared by the tape process reached 0.9 GPa and 1700 S/cm,respectively.Not only the number of layers and length of the films are controllable in this process,but also the high performance CNT composite fims can be prepared continuously.The strength and conductivity of the composite films(CNT content:22 wt%)prepared by the roller process reached 1.7 GPa and 1600 S/cm,respectively.This method is simple and suitable for preparing high strength CNT composites.CNT/Cu composite films were prepared by a similar preparation process,and the composite sheets were prepared by hot pressing sintering.Both processes can achieve high CNT content and high orientation,and provide a new way to prepare high performance CNT composites.