Study On Lamellar Nanofiller Reinforced Rfl Impregnation System And Its Coated Fiber Adhesion Properties With Rubber

Fiber rubber composites play an important role in the rubber industry,and the quality of the adhesion between them is critical for the safety and service life of rubber products.However,due to the high modulus and reaction interbess of fiber surface,the adhesion of high-performance fibers with rubber matrix is not ideal.The mechanism of fiber-reinforced rubber is recognized as the stress transfer mechanism.The traditional resorcinol-formaldehyde-latex(RFL)impregnation system establishes a strong interface connection between the fiber and the rubber.And the RFL interface layer serves as a "bridge" between the fiber and the matrix,which has a crucial influence on the physical,chemical and mechanical properties of the composite.According to the modulus transition theory,the modulus of the transition zone should be between the fiber reinforcement and the polymer matrix.Water-soluble nano fillers were added into the aqueous phase to strengthen the RFL impregnation system by establishing a reinforced and toughened interphase.The strengthening interphase can improve the efficiency of stress transfer and achieve the purpose of increasing the adhesion of fiber/rubber composites.(1)The layered silicate filler Montmorillonite(MMT)was used to reinforce the RFL impregnation system.In this paper,nylon 66 cord was used as the research object.The preparation method of MMT modified RFL impregnating solution was studied and adjusted to improve.the dispersibility of MMT in the dipping solution;FTIR,SEM,AFM and other characterization methods were approached to observe the chemical structure,surface morphology and roughness of the fiber surface.The results showed that after modification,the adhesion rate and roughness of the cord increase with the increase of MMT dosage;The dipping solution can still be evenly applied to the fiber surface to achieve Full adhesion with rubber;Dry heat shrinkage rate of cord reduced and no loss of breaking strength indicated that the modified fiber can still meet the performance requirements.,The adhesion effect test found that when the latex solid content was modified by 10wt%MMT,the fiber/rubber composite material had the best adhesion effect.Compared with the pure RFL system,the H pull-out force was increased by 24.2%.After extraction,the surface of the fiber was covered with the largest amount of rubber,and the interface damage mostly occured at the rubber matrix;the peel force was increased by 22.8%and the fiber surface coating rate after peeling failure was 100%.The mechanism of the nano-reinforced interface was explored that MMT has a good dispersion effect in the dipping solution,which can significantly improve the modulus of the RFL dipping layer.(2).In order to further enhance the enhancement effect of MMT and prevent the phase separation of the filler during the drying and curing of the dipping solution,the silane coupling agent KH550 was studied to modify the surface of sodium-based montmorillonite.The modification effects of different dosages of KH550 on clay MMT were analyzed by FTIR,XRD,TGA,etc.It was found that the layer spacing and grafting ratio of MMT increased with the increase of the amount of coupling agent,When using 30%of the coupling agent to modify,the MMT layer spacing increased from 1.22nm to 1.68nm,the surface grafting rate can reach 4.7%.TEM observed that the MMT was distributed in a cloud shape,indicating its good peeling and dispersing effect.The macro-adhesive performance test was found that the H extraction power is increased by 8.3%and the peeling force was increased by 13.0%compared with before modification.the H extraction power was increased by 32.5%and the peeling force was increased by 35.8%compared with the pure RFL system.The SEM-EDS characterization method found that a large amount of S elements accumulated in the RFL impregnation layer,and the degree of aggregation after MMT modification was lower than before unmodified.This is because the addition of fillers improves the degree of crosslinking of the interface layer,which can hinder the migration of vulcanization aids.(3)The study used graphene oxide(GO)to strengthen the RFL impregnation system.The GO modified RFL dipping solution with good dispersion effect was prepared,and it can be evenly applied to the fiber surface.The rate of cord adhesion increased with the increase of the amount of filler,and the optimal rate is around 6.1%;The reduction of dry heat shrinkage and no loss of breaking strength indicated that the modified fiber still had a high use value.After compounding with rubber,it was found that the filler with 0.5wt%GO content had the best modification effect.Compared with the pure RFL system,the H extraction force increased by 13.8%and the peel force increased by 16.4%.The modification effect of GO is weaker than MMT,this is most likely because the reasonable dipping treatment process was not used,and the poor impregnation on the fiber surface can affect the interface adhesion performance.