Study On Graphene Modified Rubber And Unstable Vulcanization System Rubber

The water-absorbing swelling rubber made of rubber-based composite water-absorbing material is one of the most common functional polymer materials.The water-absorbing swelling rubber is mainly formed by blending rubber matrix with hydrophilic components.Because of its good mechanical properties and,after water swelling,it can self-adaptive expansion seal in different gaps,water-absorbing swelling rubber widely used in tunnels,subways,caves,underwater projects,offshore oil production,and town water supply facilities.Graphene oxide(GO),an emerging two-dimensional material,is structurally identical to the graphene-based structure.The difference is that the GO sheets have a large number of oxygen-containing groups on both sides,so they have excellent dispersibility in water and provide a good prospect for their application in water-absorbing materials.However,the graphene oxide prepared by the modified Hummers method is usually an aqueous solution of graphene oxide,Polymer materials generally have relatively high degree of polymerization and are relatively stable and insoluble in water,therefore,it is with great significance to synthesize a water-absorbing material with graphene oxide and polymer materials.One of the main contents of this paper is to prepare the GO/NBR composite rubber by preparing the GO aqueous solution and NBR rubber compound;The GO/NBR water-absorbing swelling rubber was prepared with GO/NBR composite rubber as the matrix and studied.(1)Graphene oxide was prepared by modified Hmmers method,and Characterization of Graphene oxide by Fourier Infrared Spectroscopy(FIR),Scanning Electron Microscopy(SEM),Transmission electron microscope(TEM),and Wide-Angle X-ray Diffraction(XRD).Research shows,the prepared graphene oxide surface contains a large number of oxygen-containing functional groups,size ranges from several hundred nanometers to several micrometers,and the structure has a certain degree of curl.The GO/NBR compound rubber was prepared by solution blending and using acetone as a solvent to compound graphene oxide(GO)and nitrile rubber(NBR).Using XRD for characterization and macroscopic observations.Studies have shown that graphene oxide has been uniformly dispersed in nitrile rubber,and at the same time,the crystallinity of nitrile rubber has been reduced.GO/NBR rubber body is black and nitrile rubber apparent contrast,and in the light,the light can be directly through the rubber,no significant impurities in the rubber matrix,graphene oxide does not agglomerate and composite well with.nitrile rubber.(2)GO/NBR Absorbent Rubber was prepared with GO/NBR Rubber as Matrix by Mechanical Blending and Flat Sulfurization.Characterization of GO/NBR water-absorbing swelling rubber was analyzed by rotorless vulcanometer,universal tensile tester,Shore hardness tester,and water absorption test,and the effects of GO and sulfur content on the performance of GO/NBR water-absorbing swelling rubber were studied.Studies have shown that,at 160℃,the addition of GO will reduce the vulcanization efficiency of the rubber and the positive vulcanization time will be longer.The mechanical properties of rubber show that the rubber has the highest tensile strength when GO is not added,and the tensile strength decreases with the increase of the amount of GO,and the elongation at break increases,and the Shore A hardness decreases.The water absorption performance shows that the addition of GO will increase the water absorbency of rubber significantly,which is proportional to the amount of GO.When the amount of GO is 100 mg,the water absorption rate is 1203%.Although the increase of GO dosage will increase the water absorption capacity,the improvement effect is not Obviously,the mechanical properties dropped too much.Sulfur as a variable in the study of rubber properties,160℃,the addition of sulfur will increase the vulcanization performance of rubber and crosslink density will Increase.The tensile strength of GO/NBR water swelling rubber has increased with the increase of sulfur,and the break elongation shows the opposite trend,and shore A hardness increased.Water absorption performance shows that the more sulfur,the more harmful the ratio of rubber absorbs water.Taken together,when the amount of GO is 100 mg and the amount of sulfur is 0.8 parts,the overall performance is the best.The tensile strength is 5.657 MPa,the elongation at break is 1113.600%,the Shore A hardness is 75,and the maximum water absorption ratio is 1203%.In recent years,with the development of the world economy and the improvement of the industrial level,the use of rubber has been increasing.At the same time,the output of waste rubber is also rising year by year.Rubber has a stable three-dimensional network structure,making it relatively difficult to recover and degrade.Traditional rubber processing is based on existing vulcanizates.Due to the special structure of rubber,rubber treatment has different limitations.The original intention of this experiment was to search for a “cross-linking bond that can be controlled” from the root cause to prepare rubber,which we named as “unstable vulcanization system”.One of the main contents of this paper is to propose a co-curing system based on SBR,BPO and MBA,and to prepare a rubber with amide bonds as cross-linking bonds.The rubber has an amide bond as a cross-linking bond,and the amide bond can be hydrolytically broken in an alkaline environment to achieve the purpose of uncrosslinking,which is beneficial to the regeneration of the rubber.Compared with the traditional rubber with polysulfide bonds as the cross-links,the amide bonds are cross-linked with "unstable" characteristics that are cross-linkable and controllable fractures.(3)Based on styrene-butadiene rubber(SBR),a co-curing system consisting of benzoyl peroxide(BPO)and N-N methylene bisacrylamide(MBA),mechanically blended and flat-plate vulcanized to produce an "unstable vulcanization system rubber."The rubber has amide bonds as crosslinks." The rubber was characterized by a rotorless cure tester,a universal tensile tester,an aging test,a thermogravimetric analysis(TGA),a scanning electron microscope(SEM),a Fourier transform infrared spectroscopy(FIR),and an alcohol-alkali solution hydrolysis test.The effect of MBA dosage on rubber was studied.The study found that at 150℃,the vulcanization characteristics of the rubber showed that the vulcanization efficiency of rubber first increased and then decreased with the increase of MBA dosage.When the MBA dosage was 5 parts,the efficiency was the best and the crosslink density was the highest;the mechanical properties of rubber showed that when When the MBA dosage was 5 parts,the tensile strength of the rubber reached the highest value of 6.347 MPa,the elongation at break was 412.8084%,and the Shore A hardness was 60.After 150℃×24h hot air aging,the performance decreased the least and was the most stable.The effect of the alcohol-alkali solution on the vulcanization system of the rubber indicates that the rubber can be hydrolyzed in an alkaline environment,and that the hydrolyzed rubber has a mass loss in the organic solvent and the tensile strength decreases.Thermogravimetric analysis showed that the cross-linking system did indeed cross-link the rubber and the temperature at 50% mass loss was 475℃.FT-IR showed that the rubber amide bond was hydrolyzed in the alcohol-alkaline solution and the crosslink bonds were broken.SEM shows that the hydrolysis breaks the cross-linking bonds of the rubber,causing the destruction of the rubber molecular structure and making the surface texture rough and irregular.