| Fiber reinforcing materials play a key role in rubber products.The interfacial adhesion properties between the fiber and the rubber matrix are directly related to the safety and service life of the rubber products.However,due to the high degree of crystallinity and less reactive groups on the fiber surface,the interfacial adhesion between the fiber and rubber is poor.At present,the Resorcinol-Formaldehyde-Latex(RFL)dipping treatment is the most widely used fiber surface modification method in the rubber industry.However,it cannot meet the green production requirements of modern fiber reinforced rubber products because there are toxic components such as resorcinol and formaldehyde in the RFL dipping system.Therefore,the purpose of the thesis is to develop a novel environmentally friendly dipping treatment technology based on the adhesion mechanism of the traditional RFL dipping system.It not only satisfies the interfacial adhesion properties of fiber/rubber composites,but also is green and environmentally friendly.Finally,the adhesion mechanism of the new dipping system was also explored.(1)Based on the adhesion mechanism of the RFL dipping system,a adhesive M/promoter-butadiene-vinyl pyridine(VP)latex dipping system and an epoxy/curing agent-butadiene-vinyl pyridine(VP)latex dipping system were developed.The raw materials used in these dipping system are all non-toxic ingredients.In the thesis,polyester fabrics and nylon cords were used as the research object.The effects of composition ratio,latex solid content,accelerator and curing agent type,latex type,thermal curing conditions,dip pickup and nanoparticle-enhanced dip layer on the interfacial adhesion properties of fiber/rubber composites were investigated.When the ratios of accelerators A and B to adhesive M were 1:2 and 2:3,respectively,the adhesion property between PET fabric and rubber matrix was the best,and the average peel strength reached 17.2 N/mm and 17.5 N/mm,respectively,and the rubber coverage on fiber surface was 100%after peel test.Moreover,accelerator B has a better promoting effect,and the dipped polyester fabric only needs a curing treatment at 200 °C for 6 min.In addition,the pull-out force of the impregnated nylon cord/rubber composite was 96.0 N,which is comparable to the adhesion level of the RFL dipping method(97.8 N).Moreover,compared with accelerator A,the required optimum curing temperature decreased by about 10℃ by the promotion of accelerator B.When the ratio of epoxy resin G and curing agent T and D is 4:2 and 5:1 respectively in epoxy resin/curing agent-VP latex dipping system,the adhesion property between PET fabric and rubber matrix was the best.The average peel strength reached 17.4 N/mm and 17.2 N/mm,respectively,and the rubber coverage on fiber surface was 100%after peel test.In comparison,the adhesive M/promoter-VP latex dipping system has a better effect in improving the adhesive properties between the fiber and the rubber.The new dipping system meets the requirements of green production in the rubber industry and has the prospect of industrial application.(2)On the basis of these new environmentally-friendly dipping technologies,further exploration of the adhesion mechanism was conducted.The curing reaction kinetics of the resin components in the dipping system,the nanoparticle-enhanced dip layer and the migration mechanism of curatives were studied.The curing reaction between the epoxy resin G and the curing agent T is a first order reaction in epoxy resin/curing agent-VP latex dipping system,and the activation energy of the curing reaction is 73.3 KJ/mol.Due to the migration of the curatives,the sulfur content in the dip layer is 3 to 4 times that in the rubber matrix.The exploration of the adhesion mechanism is beneficial to the development and optimization of the new dipping system,and it has important guiding significance in scientific research and practical production applications. |
PDF Full Text Request