| High barrier vulcanized rubber is considered to be a vital chemical protective material due to its inherent excellent performance.However,only preventing human body to dangerous chemicals is not the optimal solution to the health problems of the wearer.Therefore,it is still worth discussing to further enhance its solvent barrier performance and solvent sensitivity.In this work,environmental friendly and non-toxic dopamine(DA)was used to reduce graphene oxide(GO),namely polydopamine modified graphene oxide(PDA-r GO)as the reinforcing filler,fluoroelastomer(FKM)and bromobutyl rubber(BIIR)as the matrix,different PDA-r GO/rubber composites were obtained by solution blending method.The mechanical properties,solvent resistance,dielectric properties and solvent sensitivity of the modified filler and its rubber composites were studied.The main research content of this work is divided into the following four parts:(1)Go was successfully prepared,and then partially reduced by DA.The results showed that the surface of GO was successfully self-polymerized by DA,and the oxygen-containing functional groups(such as-COOH)on GO were partially removed to form r GO,and the amount of DA was positively correlated with the reduction degree of GO.The reduction degree of GO can be effectively regulated by changing the amount of DA.PDA-r GO can still be stable dispersion in organic solvents(acetonitrile,tetrahydrofuran).(2)In the FKM system,in the curing process of FKM,PDA can act as the curing agent,and the catechol group of PDA may participate in the cross-linking reaction to form chemical bond with FKM and strengthen the interface effect.The results show that when the content of GO reaches 1.5 parts and the ratio of DA/GO is 1,the cross-linking density of composite material increases by 32.5% and the swelling index of butanone decreases by102.5% compared with that of pure FKM.The relative dielectric constant increases by about 375% to 43.2,and the dielectric loss is only 0.11.In addition,the four typical solvents can be well distinguished,among which the responsivity for acetone is the largest(37),with a fast response rate(26s)and stable repeatability.(3)In the FKM system,besides the content of PDA-r GO,the content of DA also has a significant influence on the reinforcing effect of FKM.The results show that when the ratio of DA/GO is 1 and the content of PDA-r GO is fixed at 1,the dispersion of PDA-r GO is better and the comprehensive properties of PDA-r GO are the best.Compared with PDA-r GO-0.5/FKM,the relative dielectric constant of PDA-r GO-1/FKM composites is increased by 116.6%,reaching about 29.0,and the dielectric loss is about 0.132.The responsiveness to acetone increased by 140.3%.On the contrary,when the amount of DA is more than 1 part,the electrical properties of the composites become significantly worse.(4)In the BIIR system,when the fixed DA/GO ratio is 1,the inhibition effect of DA on GO aggregation tendency is more obvious.The results show that the content of PDA-r GO has a significant effect on the composite properties,and the best composite properties are obtained when the content of PDA-r GO is 0.5.Compared with pure BIIR,the crosslinking density and tensile strength of 0.5 PDA-r GO modified composite increased by 57.7% and 39.6%,reaching about 8.56 MPa.The swelling index of toluene decreased by 14%,and the relative dielectric constant(4.0)of at 1 k Hz increased by 14.3%.The responsivity for methanol and butanone increased significantly,reaching 10.7 and 79.4,respectively. |
