Research On Fiber Surface Improvement Of UHMWPE/Epoxy Resin Composite-based

Ultra High Molecular Weight Polythene（UHMWPE）fiber has high strength properties similar to carbon fiber and aramid.It is superior to carbon fiber in elongation and can be used to develop high strength anti-deformation composite plates.However,the direct compound performance of UHMWPE fiber and epoxy resin is poor.This paper is made of 30 Ne/2 yarns that use UHMWPE fiber with linear density 1.21 dtex and length38 mm.The surface treatment of yarn was treated by corona treatment,potassium dichromate solution,hydrogen peroxide solution and silane coupling agent in order to make UHMWPE/thermosetting epoxy resin composites.Then the paper studies fiber morphology,properties and properties of composites.The following conclusions can be drawn:（1）After many surface improvements of UHMWPE yarn,the quality reduction rate is within the range of-4.375%²5.625%,as well as the diameter reduction rate is within the range of-0.272%¹0.626%.The corona is limited to a certain extent by time interval,and the quality and diameter of the yarn after treatment aren’t significant.The quality and diameter of silane coupling agent were respectively increased by 4.375%and 0.272%due to graft reaction on the fiber surface.When single treatment,In accordance with K₂Cr₂O₇:H₂O:H₂SO₄=7:12:130 mass ratio to prepare potassium dichromate solution 7:12:130 can obtain the minimum quality of yarn.The minimum quality is 4.76×10^-4g.Then using KH-550 silane coupling agent for dual processing with soluble potassium dichromate,the minimum diameter of yarn respectively is 0.328 mm.（2）In various treatment processes,the mechanical loss rate is within the range of-9.003%⁴8.624%.In accordance with K₂Cr₂O₇:H₂O:H₂SO₄=7:12:80 mass ratio to prepare potassium dichromate solution or in accordance with 30%H₂O₂:H₂O=70:30 mass ratio to prepare hydrogen peroxide solution,the mechanical loss of yarn is greatly increased,up to 48.624%.After the treatment of silane coupling agent,the mechanical loss is-9.003%,indicating that the treatment of KH-550 silane coupling agent can improve the mechanical properties of UHMWPE yarn and the maximum fracture strength is6321.74 cN.（3）The contact angle of yarn was reduced to a great extent after treatments,and the decrease rate was 6.482%³0.854%.In accordance with 30%H₂O₂:H₂O=70:30 mass ratio to prepare hydrogen peroxide solution,then using KH-550 silane coupling agent for dual processing.At this time,the minimum of yarn dynamic contact angle is 83.594°.The infiltration and interface bonding strength of UHMWPE fiber and resin are maximized and enhanced.（4）The inclusion rate of the modified substrate was 69.620%⁷8.978%,and the increase of the inclusion rate indicated that the permeability of UHMWPE fiber and epoxy resin is enhanced.In the case of single treatment,the quality ratio of concentrated sulfuric acid is 78.978%,which is 78.978%in accordance with K₂Cr₂O₇:H₂O:H₂SO₄=7:12:80 mass ratio to prepare potassium dichromate solution.In this way,the permeability of UHMWPE fiber and matrix is the best.（5）Improved process can effectively remove or reinforce the weak boundary layer of fiber in UHMWPE short yarn and activate the inert surface layer.In the meantime,it increases the wettability,roughness,mechanical properties and chemical reactivity of UHMWPE fiber.Potassium dichromate and hydrogen peroxide can effectively increase the UHMWPE fiber surface roughness and the content of oxygen containing functional groups.The interfacial bonding strength between UHMWPE fiber and thermosetting epoxy resin can be improved by the interaction mechanical meshing force and oxygen containing functional groups.However,the potassium dichromate and hydrogen peroxide increase the adhesion between UHMWPE fiber and epoxy resin matrix at the cost of UHMWPE fiber strength loss.KH-550 silane coupling agent can improve the adhesion of UHMWPE fiber surface as well as improve the mechanical properties of the fiber,increasing the enhancement effect between fiber and matrix by 11.255%.