Study On Preparation Of Sulfonated Graphene And Modification Of Natural Latex Composite Film

In this paper,graphene oxide(GO)/natural rubber latex(NRL)composite films were prepared by method of emulsion mixing;synthesizing graphene oxide and sulfonated graphene(SGE)by the modified Hummers method and diazonium reduction method;sulfonated graphene/natural rubber latex(SGE/NRL)composite films were prepared by the methods of emulsion casting molding and then vulcanized in hot air.The effect of0.1~1.0phr SGE on the basic properties of compound latex was studied.We researched the two kinds of composite films by some characterization methods such as the vulcanized characteristics,tensile property,anti-aging properties,solvent resistance,thermal stability and gas impermeability,etc.Part Ⅰ,GO/NRL composite films were prepared by emulsion mixing method.Effects of composite films on the vulcanized characteristics,the tensile properties,anti-aging properties,thermal stability and gas permeability of composite films were investigated by different dosages of GO.Through the pictures of SEM,the results showed that the pure NRL’s cross-section has vug like honeycomb.It was account for that the evenly dispersion of GOs in natural rubber matrix is improved which making up for the defects.Meanwhile,composite films had improved the crosslinking density,tensile properties,anti-aging properties,thermal stability and gas permeability with the addition of GO.When the GOs in an amount of 0.5 phr,the tensile strength of the composite films reached 27.84 MPa.Compared to the pure natural rubber latex,the tensile strength of GO/NRL composite film has increased to 40%.Part Ⅱ,we synthesized graphene oxide by the modified Hummers method.With p-aminobenzenesulfonic acid as modifier,sulfonated graphene(SGE)was prepared by diazonium salt method to improve the compatibility of graphene with natural rubber.FT-IR、XRD、SEM、TEM、AFM and other characterization methods were used to contrast and analysis the sample of GO and SGE.The results showed that sulfonic acid group was grafted on the graphene surface successfully.Compared with GO,SGE has fewer structural defects and higher regularity.Last but not at least,it improves the hydrophilicity and thermal stability of graphene.Part Ⅲ,using the SGE as filler,SGE/NRL composite latex was prepared by the methods of emulsion casting molding and then SGE/NRL composite films were vulcanized in hot air.Effects of SGE on the vulcanized characteristics,tensile properties,thermalstability,gas permeability,anti-aging properties,solvent resistance and microstructure of the composite films were investigated.The results showed that,with the increasing of SGE amount,the tensile strength of the composite film increased first and decreased then,and the tensile strength reached the maximum value of 37.87 MPa when SGE was 0.8 phr.Furthermore,the elongation at break of the composite film decreased first and then increased,The shore hardness increased gradually,thermal stability,solvent resistance and gas impermeability were improved.SGE dispersed uniformly in NRL,and the interface bonding function was improved.