Research On The Pretreatment Of Aramid Pulp And Its Reinforced Hydrogenated Nitrile Rubber Properties

Rubber products play an important role in people’s production and life today.In various fields such as transportation,aerospace,petrochemical,etc.,rubber materials can be seen everywhere.In order to better face the complex working environment,the performance improvement of rubber materials has been continuously studied.Aramid pulp（AP）has the characteristics of high strength and wear resistance,which can strengthen rubber materials very well,but its entanglement between fine fibers leads to agglomeration and is difficult to disperse.Therefore,aramid pulp is pretreated to disperse in rubber materials.Uniformity becomes the research direction of this subject.In this paper,hydrogenated nitrile butadiene rubber（HNBR）was used as the matrix,silica as the basic filler,and AP as the reinforcing agent to systematically study the reinforcing effect of the pretreated AP on the rubber.（1）On the basis of processing technology,NR and ENR are used to pre-disperse AP with the characteristics of good viscosity and large plasticity to prepare NR-AP and ENR-AP reinforcing materials.Industrial grade silica 1165MP is used as filler.Since ENR and HNBR have similar structures,ENR-AP can have a more uniform dispersion effect in HNBR.The 1165/ENR-AP/HNBR rubber composite reinforced with 8 phr ENR-AP has a tear strength of 52.6k N/m,a hardness of 76.9°,and better elasticity.（2）Silica was prepared by sol-gel method（S）and co-precipitation method（C）.The rich hydroxyl groups and the amide in the AP structure were bonded to form hydrogen bonds.The silica was loaded on the surface of AP and carried out between fibers.To achieve the effect of dispersing AP,SiO₂（S）-AP/HNBR and SiO₂（C）-AP/HNBR rubber composites were prepared.The SiO₂（C）-AP prepared by the co-precipitation method has the best dispersion effect.The tensile strength of the SiO₂（C）-AP/HNBR rubber composite containing 5 phr AP is increased from 7.07 MPa to 22.75 MPa without modification,and the tear strength is 59.88 k N/m.（3）The industrial grade silica 1165 MP was blended with AP by the method of physical ultrasonic stirring,and 1165 was filled in the gap of AP as a release agent to achieve the purpose of dispersing AP,and then the 1165-AP/HNBR rubber composite material was prepared.The tensile properties of 1165-AP/HNBR reached 28.91MPa,the tear strength was 74.43 k N/m,the dispersibility of 1165-AP was enhanced,and the performance was improved significantly.