Study On Preparation And Properties Of Modified Graphite/Carbon Black/Natural Rubber Composites

Panzhihua has abundant graphite resources,ranking third in the country,but its comprehensive utilization level is low.In order to improve its comprehensive utilization level and expand the application field of graphite,the deep processing and application research of graphite has become a hot spot.In this paper,stearic acid,phenolic resin and polyacrylate were used to modify graphite oxide,expanded graphite and graphene oxide respectively.The properties of modified graphite/natural rubber composites were studied by blending modified graphite with natural rubber.The effect of the amount of carbon black on the properties of the modified graphite/carbon black/natural rubber composite material can realize the purpose of partially or completely replacing the carbon black to enhance the natural rubber,and promote the development of graphite resources and expand the application field of graphite.The phenolic resin was used to impregnate the graphite oxide.The results show that the surface roughness and thermal weight loss of the graphite modified by the phenolic resin increase,the reactive functional groups increase,and the dispersibility increases.When the graphite particle size is less than 2500 mesh,the graphite oxide and the phenolic resin The tensile strength of the modified graphite oxide/natural rubber composite prepared by mass ratio less than 5:1,immersion time 4h and ultrasonic dispersion for 40 min is better.When the amount of modified oxidized graphite is 20 parts,the tensile strength of the composite is The maximum is 26.8MPa,and the wear ratio is the smallest,0.98%.The modified graphite oxide/carbon black/natural rubber composite material increases with the increase of the amount of carbon black,and the tensile strength and the tensile stress increase first and then decrease.The elongation gradually decreases.When the amount of modified oxidized graphite is 20 parts and the amount of carbon black is 10 parts,the tensile strength value is the largest and the wear ratio is the smallest,which is 30.2 MPa and 0.76%,respectively,compared with pure natural rubber.Tensile strength increased by 379.4%,wear ratio decreased by 35.6%,minimum torque and maximum torque increased,and vulcanization time increased.After the expanded graphite is modified by polyacrylate,the intrinsic structure of graphite does not change.The surface of expanded graphite is coated with a large amount of polyacrylate,the thermal weight loss is increased,the active functional group and roughness are increased,the dispersibility is enhanced,and the reinforcing effect on natural rubber is enhanced.It is weak;when the mass ratio of acrylate prepolymer to expanded graphite is 5:1,the expansion volume is 10mL/g,and the amount of modified expanded graphite is 5 parts,the tensile strength of modified expanded graphite/natural rubber composite is the most The value is 9.1 MPa and the wear is low,which is 1.24%.The modified expanded graphite/carbon black/natural rubber composite material increases with the increase of the amount of carbon black,and the elongation at break and the wear ratio gradually decrease.The tensile strength is 5 parts when the modified expanded graphite is used,and the maximum amount is 20.5 MPa when the amount of carbon black is 20 parts.The wear ratio is 1.08%,and the tensile strength is improved compared with the pure natural rubber.At 225.4%,the wear ratio was reduced by 8.5%.The graphene oxide is modified with stearic acid.The stearic acid is coated or embedded on the surface or interlayer of the graphene oxide.No new substances are formed,and the modified graphene oxide layer spacing is reduced,and the thermal weight loss is increased.,the active group and roughness increase,the dispersibility is improved;when the mass ratio of graphene oxide to stearic acid is 250:9,the reaction is carried out at 60~70 ° C for 6 h,and the stearic acid modified oxidation prepared by ultrasonic dispersion for 60~80 min The performance of the composites is better when the graphene is blended with the natural rubber.With the increase of the amount of modified graphene oxide,the tensile stress of the composite increases,the elongation at break decreases,the curing time is shortened,and the tensile strength is modified.When the amount of graphene oxide is 5 parts,the maximum value is 15.8 MPa,and the wear ratio is the lowest at 1.05%.The use of modified graphene oxide and carbon black can significantly improve the tensile strength and wear resistance of the rubber.With the increase of the amount of carbon black,the elongation at break of the composite decreases and the tensile stress increases.When the modified graphene oxide is 5 parts and the carbon black is 30 parts,the tensile strength of the composite is the largest,which is 32.6MPa,and the wear ratio is the lowest,which is 0.73%,with pure natural oak Compared to enhance the tensile strength of 417.5%,38.1% reduced wear ratio.