| The clay/carbon composites were prepared via hydrothermal treatmengt using clay minerals as template and chitosan as carbon source.The effect of incorporating clay/carbon on mechanical,thermal properties and thermal conductivity of carbon fiber/epoxy composites was investigated.The main conclusions were described as follows:(1)The halloysite/carbon(HNT/C)composites were obtained via hydrothermal treatment of halloysite and chitosan.Carbon fiber/epoxy(CF/EP)composites adding HNT/C were fabricated via hot pressing method.The results showed that the chitosan carbonized as nanocarbon with a thickness of 10-30 nm deposited on the surface of halloysite.The halloysite/carbon was rich in organic functional groups such as-CH,C=C,C=O and-NH.When the mass ratio of chitosan to halloysite was 0.5,the incorporation of HNT/C leads to 19.2%and 31.6%increases in the flexural strength and modulus of CF/EP composites,respectively.The storage modulus and thermal conductivity also increased by 20.4%and 113%respectively.The reinforcing effect of HNT/C was obviously better than those of halloysite and hydrothermal carbon.The synergistic effect of halloysite and hydrothermal carbon promoted the dispersion of HNT/C in resin matrix,increasing the contact area between HNT/C and epoxy matrix.The amino group in carbon coated on halloysite surface enhanced interfacial bonding between HNT/C and epoxy matrix through chemical bonding which was beneficial for the load transfer and thermal transmission.With the futher increasing of carbon content in HNT/C by increasing the mass ratio of chitosan and halloysite,the mechanical properties and thermal conductivity of CF/EP reduced because of the agglomeration of HNT/C.(2)The montmorillonite/carbon(MMT/C)composites were obtained via hydrothermal treatment of montmorillonite and chitosan.MMT was loaded with a certain amount of carbon,and some organic groups such as-CH,C=C,C=O and-NH were accompanied by MMT/C.When the mass ratio of chitosan to montmorillonite was 0.5,the incorporation of resultant MMT/C lead to 12.4%and 17.1%increases in flexural strength and modulus of CF/EP composites respectively.This was due to the synergistic effect of montmorillonite and carbon.The amino group of carbon in MMT/C was beneficial for the interfacial bonding between MMT/C and epoxy resin through chemical bonding which promoted the load transfer between epoxy matrix and MMT/C.(3)The simultaneous adding of HNT/C and MMT/C to CF/EP composites was slao investigated.On the one hand,one dimensional HNT/C could link adjacent two dimensional MMT/C and prevent MMT/C mutual stacking.On the other hand,the platelet MMT/C seperated two adjacent HNT/C,inhibiting the second aggregation of HNT/C.HNT/C-MMT/C three dimensional network structure form which lead to the dispersion ability of additive in epoxy matrix.Correspondingly the contact area between additive and epoxy resin increased which promoted stress transfer and thermal transmission between additive and epoxy matrix.When the mass ratio of HNT/C to MMT/C was 4:1,the flexural strength and modulus of CF/EP were increased by 25.9%and 35.3%,resoectively.And the storage modulus and thermal conductivity were increased by 24.1%and 159.8%,respectively.The reinforcing effect of HNT/C-MMT/C was obviously better than that of HNT/C and MMT/C. |
