Surface Modification Of Submicron Aramid Pulp Short Fiber And Study On Structure And Properties Of Rubber-based Composites

Para aramid pulp(PAP)is a kind of differentiated products originating from Para-aramid fibers(PAF),could be prepared by chopped PAF fibrillation.Because of the same chemical structure with PAF,PAP well keep the original great properties of PAF,such as high modulus,first-class strength,outstanding temperature resistance,abrasion resistance,chemical corrosion resistance,dimension stability and so on.Besides PAP also has a very unique microstructure---A large number of micro/nano-sized superfine fibers through the fibrillation attach to the backbone fiber surface.In the use of PAP,these superfine fibers will mutual entanglement and form together,with the addition of stable chemical properties and low surface reactivity of PAP,all of this will lead to form superfine fiber reunion points which can't be evenly dispersed in substrate,and then causing product performance defect.There is no doubt that the problems greatly have restricted the application and promotion of aramid pulp.Through to the AP interface modification and pretreatment,the paper has solved the above problems well.According to this method,AP can be dispersed evenly in the rubber matrix,and the micro/nano-sized superfine fiber can be at full stretch in the matrix with little entanglement,thus AP and the substrate will have a stronger interface bonding effect,further to improve the effect of ppta-pulp integral reinforcement.Specific experimental study summarized below:1?By FTIR,EDS,SEM and TGA testing means,I made a comprehensive and systematic research about aramid fiber and aramid pulp,analyzed the relationship between the microstructure and macro properties,summarized the rules.Clearing ppta-pulp application advantages and disadvantages.Aiming at solving that AP easily tangled together and scattered difficultly,the author found a way---Pretreatment and Modification.2?Traditional ppta-pulp masterbatch show a poor dispersion performance in practical application,small molecule additives easily migrate to the surface of masterbatch in storage as well,consequently,having a bad influence on product performance.The author reconstructed the traditional ppta-pulp masterbatch formulation and process optimization.Use highly reactive polyisobutene(PIB)with molecular weight at around 1000 as a new isolation agent.Using PIB better liquidity at high temperature and higher viscosity at normal temperature.Through the rapidly mixing process,PIB rapidly infiltrates into Micro/nano fibers,playing the role of isolation dispersion.At the same time,we utilize other additives strengthening the interfacial interaction,enhance the isolation effect of PIB,and as a result,we will get the Aramid pulp pretreatment with a good performance.And then,through high shear dispersion,fine dispersion,extrusion and pelletization,finally,we will get high-activity pre-dispersion aramid pulp masterbatch(PAPM).3?We made a structure and performance analysis for PAPM,Verifying its excellent performance.Next,we confirmed the best accessible conditions such as dosage,roller spacing,fiber orientation etc.and then,we prepared AF/EPDM composite materials and AF/NBR composite materials.Observe the decentralized state of AF in both of rubber matrix.Explore the structure and properties of the composite material,and make a detailed analysis about processing rheological properties of mixing rubber,mechanical properties of vulcanizates,dynamic mechanical properties,etc.