Preparation And Characterization Of Ionic Liquid/Grapehen/Phenolic Rsins Composites

Filler conductive polymers have been widely used in various fields due to their own advantages.Graphene is an emerging material in the field of nanotechnology in recent years.It has high electron mobility,good thermal stability and large specific surface area,and is widely used in polymer matrix composites.However,there are some technical problems,such as large van der Waals force between graphene sheets,easy agglomeration,large amount of graphene addition,and decrease of mechanical properties of the composite material.There are some advantages of ionic liquid,such as good electrical and thermal conductivity,high thermal stability,strong electrostatic field,wide electrochemical window and so on,used for improve the agglomeration phenomenon of filler in polymer composites,improve the dispersion of conductive filler,and then improve the conductivity of composites.Based on these advantages,we synthesized several ionic liquids,and introduced ionic liquids into conductive polymer composites,and systematically discussed the properties of the composites such as conductivity,mechanical properties,thermal stability,glass transition temperature and so on.1.Three ionic liquids,dimethylaminoethyl methacrylate maleenediate(DMAEMA-MA),1,10-bis(1-vinylimidazole)decyl bromide([DMIM]₂Br₂),1,2-dimethyl-3-butylimidazole bromide([BMMIM]Br),were synthesized by quaternization method and characterized by NMR and IR.The phenolic resin composites were prepared which modified by ionic liquid.It was found that the thermal stability and the toughness of phenolic resin were improved by the addition of ionic liquid The volume resistance was reduced,but the glass transition temperature increased first and then decreased of[DMIM]₂Br₂was(0-1.0)wt%,[BMMIM]Br.DMAEMA-MA decreased the glass transition temperature of ionic liquid when the content was(0-1.0)wt%.The SEM images showed that the unmodified phenolic resin had more aggregates on the impact fracture surface and the curing was not uniform,while the modified phenolic resin had less aggregates on the impact fracture surface and the curing was uniform.2.The research of preparation and properties of graphene/phenolic resin composites.The composite material was prepared by blending and hot pressing.The addition of graphene improved the mechanical properties of phenolic resin,and the optimum mechanical properties were obtained when the addition amount was 15 wt%.The glass transition temperature increased slightly with the increase of graphene content.Graphene reduced the decomposition temperature of the composites at thermogravimetric loss of T_5%and T_10%.The electrical conductivity increased with the increasing of graphene content.SEM images shown that the graphene content of 15 wt%had the best dispersion effect,the conductive network was the most perfect,when the content of 20 wt%appears agglomeration phenomenon.3.The research of preparation and properties of ionic liquid/phenolic resin/graphene composites.The composites were successfully prepared by vacuum filtration and hot pressing.The results showed that the thermal stability of the composites was improved with the addition of ionic liquid.The thermal decomposition temperature of[DMIM]₂Br₂increased 104?when the content of[DMIM]₂Br₂was 9 wt%and under T10%.When the ionic liquid was added 5 wt%,the electrical conductivity of the composite reached the maximum of 0.00355 S/cm.When the ionic liquid content was(3-9)wt%,the glass transition temperature decreased.SEM images showed that the agglomeration phenomenon is significantly reduced after the addition of ionic liquid,the arrangement of graphene sheets was obviously compact,and the outline was clear,and the dispersion state was significantly strengthened.4.The research of preparation and electrical properties of KH570-graphene/ionic liquid/phenolic resin composites.?-methylacryloxypropyl trimethoxy silane(KH570 silane coupling agent)is a silane coupling agent that can effectively improve the dispersion and adhesion of the filler in the matrix.KH570-graphene/phenolic resin composites and[DMIM]₂Br₂/KH570-graphene/phenolic resin composites were prepared.The results showed that the electrical and mechanical properties of the KH570-graphene/phenolic resin composites were improved,the electrical conductivity of the composites were improved by adding[DMIM]₂Br₂,but the improvement is not significant,the mechanical properties were greatly improved.