Preparation And Key Technology Of Carbon Nanotubes Modified Polytetrafluoroethylene Composites

In view of the good performance of PTFE and CNTs, we prepared CNTs/PTFE composites by dry blending method successfully. In-depth analysis of the dispersion of CNTs in PTFE matrix resin and combination of the materials, we got the optimal preparation process of CNTs/PTFE composites. The main results are as follows:(1) Through study the dispersion effect of CNTs treated by CTAB, KH-560and mixed acid, the results show that the CNTs that modified can increase the active groups on the surface in a certain extent, improve the hydrophilism, reduce the agglomeration. So the dispersion stability of CNTs suspension are improved obviously. The CNTs that modified by CTAB has the best dispersion and dispersion stability.(2) By study the Influence of the preparation process route and process parameters that effect the properties of composites, we get access to the optimum method that prepare CNTs/PTFE composites.(3) The mechanical properties, thermal properties and electrical conductivity of the composites were studied. The results show that the better surface treatment and dispersion will get a substantial increase in the tensile strength, elongation at break, thermal conductivity and electrical properties in a low content; the compression rate and friction coefficient of the composites is increased; the resilience and creep properties of the composite have a small amount of change compared with pure PTFE; we also found that the crystallinity were reduced; By study the comprehensive properties of the composites, the study found the composites in which the CNTs modified by CTAB has the best comprehensive properties. When the content is1%, the tensile strength, elongation at break, thermal and electrical conductivity are increased by25.7%,27.2%,22.4%,25.8%compared with pure PTFE.