Interfacial Adhesion Between High Performance Fiber And Rubber And Its Evaluation Method

Technora fiber is a kind of high-strength para aramid fiber with the third monomer introduced in the synthesis process.It has the characteristics of high strength,large modulus,large elongation at break,high temperature resistance and so on.In order to improve the interfacial adhesion between Technora fiber and rubber matrix and apply it to the belt of radial aviation tire,the surface treatment and modification of Technora fiber are needed.Resorcinol(R)-formaldehyde(F)-latex(L)impregnation system is a method of coating fibers to improve the adhesion between fibers and matrix materials.In this study,the fiber surface modification methods such as RFL two bath dipping system,RFL filler reinforcement system and hydroxyl acrylic amino resin environmental protection dipping system were used to treat Technora fiber,and the adhesion between Technora fiber and NR/SBR rubber matrix under these treatment methods and different reaction conditions were studied to explore the best reaction conditions of different treatment methods.RFL can significantly improve the adhesion between Technora fiber and NR/SBR rubber.When the R/F molar ratio is 1/1.8,the mass ratio of R-F resin to VP latex is 0.17,and the p H value of the dipping solution is between 9-10,RFL can improve the adhesion between Technora fiber and NR/SBR rubber the most,with a pumping force of 182.0N,a stripping force of 19.1N,an aging retention rate of 83%,and a dynamic fatigue number of 12633.By means of FTIR,XPS,TGA and SEM,it was verified that resorcinol reacted with formaldehyde to form a resin structure containing hydroxymethyl group.RFL formed a stable impregnation layer on the surface of the fiber,and the interface failure between Technora fiber and NR/SBR rubber occurred in the interior of the rubber matrix.The use of multi walled carbon nanotubes(CNTs)can enhance the filler of RFL and further improve the adhesion between Technora fiber and NR/SBR rubber.Adding 0.03 g sodium dodecyl sulfate(SDS)and0.03 g GTCO-210 CNT to every 100 g RFL can obtain the best CNT reinforced RFL impregnation solution.Compared with RFL,the extraction force is 233.0N,increased by 28%,the stripping force is increased by 20%,and the dynamic adhesion is improved by 1.68 times.The effect of pre condensed RF-L impregnation solution and traditional RFL on improving the interfacial adhesion between Technora fiber and NR/SBR rubber is basically the same.Isocyanate(CBI)improved the interfacial adhesion between Technora fiber and rubber,but the improvement of waterborne epoxy resin was not obvious.Hydroxyl acrylic acid amino resin latex dipping solution(HAAL)was used to dip Technora fiber.When the mass ratio of hydroxyl acrylic resin to amino resin was 3 and the mass ratio of hydroxypropyl ammonia resin to latex was 0.5,the performance of HAAL was the best,and the extraction force was 165.4N,which reached 90% of RFL.The extraction force of CNT enhanced prepolymerization RF-L increased by 5.6%,reaching 106% of RFL,and the extraction force of CNT enhanced HAAL increased by 6.7%,reaching97% of RFL.Through FTIR characterization,it was verified that the synthesis reaction of HAA resin was ether exchange,and it was proved that HAAL could form a stable dipping layer on the fiber surface.Technora-PA66 blended fiber was formed by adding PA66 into Technora fiber,and the elongation at break of the fiber reached 9.9% through structural design.When the R/F molar ratio is 1/1.8,the mass ratio of m-nail resin to VP latex is 0.17,and the p H value of dipping solution is 10,the prepared RFL has the greatest improvement on the adhesion between Technora-PA66 fiber and NR/SBR rubber,the extraction force is 249.6N,the stripping force is 35.2N,the aging retention rate is 80%,and the dynamic fatigue times is 34420.By adding antioxidant and filler into the rubber matrix material,the aging retention rate can be increased to 95%.By means of XPS,TGA and SEM,it was proved that RFL formed a stable impregnated layer on the fiber surface,and the interface failure between Technora-PA66 fiber and NR/SBR rubber occurred in the rubber matrix.