Study And Development Of UHMWPE Fiber Knitted Fabric Composites

UHMWPE is emerged after carbon fiber and Kevlar fiber and becomes the third highest strength and highest modulus fiber in the world.At present the research on UHMWPE fiber knitted fabric composites is not varied,especially researches on mixed weaving and knitting.The aims are to deal with UHMPWE in different chemical methods,to analyze effects of chemical methods on UHMPWE and choose a more suitable method,that is a combination of K₂Cr₂O₇ and H₂SO₄.The most suitable scheme to modify UHMPWE is received by the single factor experiment and orthogonal test.Structures of knitted fabrics and Co-Woven-Knitted are analyzed to use in kinds of fields.Further,the compounding process is studied and the basic mechanical properties of composite materials are tested and characterized.Firstly,four representative chemical modification combinations are chosen to modify UHMWPE fiber.As far as surface modification,the combination of KMnO₄ and H₂SO₄ is the most effective,followed by the combination of K₂Cr₂O₇ and H₂SO₄ and the combination of H₂O₂ and HNO₃ is the least effective.As far as producing oxygen-containing groups and the cohesiveness of fiber and resin,the combination of KMnO₄ and H₂SO_4,and the combination of K₂Cr₂O₇ and H₂SO₄ are more effective than the other combinations.But the strength of UHMWPE fiber which is done by the combinations of KMnO₄+H₂SO₄ can be reduced.The combination of K₂Cr₂O₇ and H₂SO₄used by modifying UHMWPE fiber is worth promoting in comprehensive consideration.Secondly,the most suitable modified process is analyzed by the single factor experiment and orthogonal test,that is the combination ratio of K₂Cr₂O₇ and H₂SO₄ is7:12:8,63?and 10min.The shear performance between UHMWPE fiber modified and resin increases 60%as well as the roughness and the specific surface area of its surface.Thirdly,six kinds of representative fabrics are designed and their sinking depths are confirmed through knitting.The sinking depth of full gauge 1×1 rib should be bigger than that of the other structures.Fabrics basic parameters are tested and analyzed and the results are suitable to the requirements of composite materials.In the meantime,some problems are summarized and solutions accordingly are put forward.Finally,UHMWPE fiber knitted fabrics are selected for reinforcement and E-51epoxy resin as matrix to prepare UHMWPE fiber knitted fabric composites.Tested many times,the matrix mixed process is ascertained,that is:the ratio of epoxy resin and polyamide resin is 10:3,20min and 50?as well as the best hot-pressing process and composite manufacturing processes.Subsequently,mechanical properties of stretch,bending,compression and inter-laminar shear on UHMWPE fiber knitted fabric composites are tested and analyzed which provides a theoretical foundation for further research and application on high performance fiber knitted fabric composites.