Preparation,Structure And Properties Of Fluoroelastomer Nanocomposites

In recent years,the research of fluoroelastomer(FKM)nanocomposites becomes one of hotspots.Improving the dispersion of nanomaterials(such as montmorillonite,graphene,carbon nanotubes)in FKM matrix and strengthening the interfacial interaction between FKM molecules and nanomaterials are two crucial factors to realize the high performance of FKM nanocomposites.In this paper,the chemical modification of nanomaterials and new materials processing of FKM nanocomposites were studied,which can provide environment-friendly processing and high performance of FKM nanocomposites.The research contents are as follows.Firstly,amino-functionalized multiwall carbon nanotubes(MWCNT-A)were prepared successfully via ethylenediamine(EDA)grafting onto the side walls of caryboxylated multiwall carbon nanotubes(MWCNT-COOH).MWCNT-COOH and MWCNT-A nanofillers were characterized by FT-IR,XPS,Raman spectra and TEM analysis.Simultaneously,FKM/MWCNT-COOH and FKM/MWCNT-A nanocomposites were prepared by mechanical blending.The effect of MWCNT-COOH and MWCNT-A loadings on the mechanical and electrical properties,thermal conductivity,curing behaviors,swelling ratio and apparent crosslinking density of the corresponding nanocomposites were investigated,respectively.FKM/MWCNTs nanocomposites were characterized by FESEM,TEM,TGA-DTG and DMA analysis.The crosslinking mechanism of FKM/MWCNTs nanocomposites was also elaberated.The results show that the mechanical,electrical properties and thermal conductivity of FKM/MWCNT-A namocomposites are better than those of FKM/MWCNT-COOH nanocomposites due to the homogeneous dispersion of MWCNT-A in the FKM matrix and some-C=N-bonds generated between FKM moleucules and MWCNT-A.Secondly,FKM/MMTs nanocomposites were prepared by fast evaporation mixing and melting mixing.The effect of MMT loadings on the curing behaviors,mechanical and dynamic mechanical properties of the FKM/MMT nanocomposites prepared by two different processing methods were investigated,respectively.Pristine FKM,MMTs or FKM/MMTs nanocomposites were characterized by FESEM,TEM,XRD,TGA-DTG and RPA analysis.The results show that exfoliated or intercalated MMT platelets are uniformly dispersed in the FKM matrix via fast evaporation mixing.FKM/MMT nanocomposites prepared by fast evaporation mixing possess a higher tan?max and weaker Payne effect than those prepared by melting mixing.Besides,the mechanical properties of FKM/MMT nanocompsites are improved and the optimum curing time is prelonged with the increasing of MMT contents.When the MMT content is 2.5 phr,the FKM/MMT nanocomposites prepared by fast evaporation mixing show the optimum mechanical properties.