Research And Development Of Aramid Fiber And Ultra-strong Polyethylene Fiber Reinforced Composites

Aramid fiber and ultra-strong polyethylene fiber are two kinds of high performance fibers,which are widely used in today's application.At present,the aramid fiber and ultra-strong polyethylene fiber knitting reinforced composite is rare,especially the research of aramid and ultra-strong polyethylene fiber knitting reinforced epoxy vinyl ester resin composite is still at the primary stage.This thesis aims at adopting chemical crosslinking methods to modify the aramid fiber and ultra-strong polyethylene fiber,by using single factor test and orthogonal test,the optimal modification scheme of silane coupling agent KH-550 was analyzed,at the same time,designed and knitted six reinforcement fabric,then discussed the composite technology of fabric and resin,finally carried on the test and analysis of mechanical properties of the corresponding composite.Through single factor test,discusses the influence of aramid fiber and ultra-strong polyethylene fiber under different treatment conditions(concentration,temperature and time)of KH-550,the results show that after treatment,the breaking strength of the aramid fiber first increased and then decreased,the interfacial shear strength has been increased and improved by 0.51% to 23.67%;after treatment,the breaking strength of the ultra-strong polyethylene fiber also shows a trend of first increased and then decreased,the interfacial shear strength has been increased and improved by 1.89% to 60.10%.The three factors of the orthogonal test of KH-550 modified aramid fiber were: the treatment concentration was 15%,17.5%,20%,the treatment temperature was 45 ?,50 ?,55?,the treatment time was 5h,6h,7h;the three factors of the orthogonal test of modified ultra-strong polyethylene fiber were: the treatment concentration was 12.5%,15%,17.5%,the treatment temperature was 45 ?,50?,55 ?,the treatment time was 5h,6h,7h.Using orthogonal test,the optimal process for the KH-550 modification of aramid fiber was determined as follows: concentration 20%,temperature 55?,time 7h;the optimal technology of modified ultra-strong polyethylene fiber was: concentration 17.5%,temperature 55 ?,time 7h.Using the optimum silane coupling agent modification process for the treatment of aramid fiber and ultra-strong polyethylene fiber,the properties of aramid fiber and ultra-strong polyethylene fiber were tested and compared before and after treatment,the results show that after treatment the wetting property of the aramid fiber and ultra-strong polyethylene fiber was enhanced.;the surface roughness and the specific surface area increased,the number of the active groups on the fiber surface increased,and the thermal properties of the fibers were almost unaffected;adhesion of the fiber and resin was improved.Six kinds of reinforced fabric were designed and knitted,which showed the characteristics of various fabrics.The basic parameters of all kinds of fabrics are tested,and they meet the requirement of composite.At the same time,it summarizes the technical problems which are easy to appear in knitting,and gives the corresponding solutions.Aramid fiber and ultra-strong polyethylene fiber reinforced fabric were used as reinforcing material and epoxy vinyl ester resin as matrix.Through many tests,the suitable matrix ratio process was determined,and the mass ratio of epoxy vinyl ester resin,curing agent and accelerator was 100:2:1.Then,test and analysis the tensile,bending,compression and interlaminar shearing strength properties of the prepared composites.It provides some references for the research and application of knitted reinforced composite in the future.43 Figures,25 Tables,116 References.