| With the rapid development of electronic information technology,the demand for high-performance conductive materials has gradually increased.As a new type of conductive materials,conductive polymer composites（CPCs）have the advantages of low cost,low density and corrosion resistance compared with traditional metal materials.Therefore,CPCs are gradually replacing traditional metal materials in aerospace,automobile manufacturing,electrical engineering,wearable electronic products and other fields.At present,there are many difficulties in the preparation of CPCs,and the dispersion of conductive fillers in the matrix is the most prominent problem.To solve this problem,three novel CPCs were prepared by different methods,The main research contents and achievements are as follows:（1）taking biodegradable polymer PBS as the research object,PBS/CNT composites with different content of carbon nanotubes（CNT）were prepared by melt blending method,and the foam materials were prepared by supercritical CO2 pressure foaming method.The results showed that the electroosmotic filtration threshold（φ）of PBS/CNT foam was about 0.6wt.%,which was 80%lower than that of the corresponding composite material.When the CNT content of PBS/CNT foam is 5.0wt.%,the conductivity（σ）is67.4S/m,which is 2.1 times higher than that of the corresponding composite material.Due to the introduction of cell structure,the tensile stress of cell growth during the foaming process makes the agglomerated CNTs peel off,which significantly reduces the contact resistance between adjacent CNTs,and the CNTs form an obvious conductive network structure on the cell wall.（2）In order to further improve the dispersion of CNT in polymer matrix and construct efficient conductive network,the third phase polymer polytetrafluoroethylene（PTFE）was added to prepare PBS,PBS/CNT,PBS/CNT/P500 and PBS/CNT/P5（P500and P5 represent two kinds of PTFE with different particle sizes of 500μm and 5μm respectively）by melt blending method.The results show that theσof PBS/CNT/P5 is the highest at 3.0wt.%CNT,reaching 23.8S/m,which is 280%and 475%higher than PBS/CNT and PBS/CNT/P500,respectively.The small-scale P5 has no in-situ fibrillation in the composites,and plays a role of"ball milling"in the processing,which further promotes the dispersion of CNT.Finally,the electrical conductivity of PBS/CNT/P5 foamed material was improved most significantly,reaching 54.05S/m.（3）In order to further construct an effective conductive network and reduce the content of conductive filler,PBS/CNT-Ⅰ composites with isolated conductive structure were prepared by electrostatic coating hot pressing process（low temperature and high pressure）,and compared with other three different processes（II electrostatic coating hot pressing（low temperature and low pressure）,Ⅲ electrostatic coating hot pressing（high temperature and low pressure）,IV melt blending hot pressing（high temperature and low pressure））Contrast.Subsequently,PBS/CNT-Ⅰ foam was prepared by supercritical CO2foaming process.The results show that at 1.0wt.%CNT,theσof PBS/CNT-Ⅰ complex is21.4S/m,which is 12 times,381 times and nearly 5 orders of magnitude higher than PBS/CNT-Ⅱ,PBS/CNT-Ⅲ and PBS/CNT-Ⅳ,respectively.At the same time,the conductivity of PBS/CNT-Ⅰ foam material is 38.9S/m,which is 82%higher than that of PBS/CNT-Ⅰ composite material with the same CNT content. |
