The Preparation And Properties Of Poly(urethaneureas)/Epoxy-resin Composites

The Preparation and Properties ofPoly(urethaneureas)lEpoxy-resin CompositesAbstractIn this paPer, p o ly(urethaneure as)/ePoXy- re s in c omP o s ite s wereprepared by in-situ multiphase polymerization, then the stmcture andproperties of the composites were studied by tensile test, impact test,DSC,TG and SEM et al.The effects of different factors such as themolecular weigh of poly(urethaneureas) and its addition on themechanical properties and thermal stability of the composites had beenstUdied .And the difference of curing reaction activation energy(Ea)between the pure epoxy-resin curing system and the compound curingsystem was studied.The results show that the poly(urethaneureas) have crosslinkingnetwork with the epoxy resin and fOrm interpenetration polymernetWork.The soft segments of poly(urethaneureas) fOrm aggregates andinitiate the ambiellt matrix resin to create micro-fracture to absorbimpact energy .Moreover, the soft segments aggregates can createself yield deformation to absorb impact energy, accelerate the matrix toyield and occur a brittle-ductile transition.Wth the addition ofpoly(urethaneureas),the mechanical properties are largely improvedand thermal stability of the composites does not decrease.Thepo ly e ster-p o ly(urethaneure as ) o f TD I c an make the imp act strengthincrease by l14%,tensile strength increase by 44%.The polyester-poly(urethaneureas) of MDI can make the impact strength eIiliance by1 32%, tensile strength enhance by 41 %.The polyether-poly(urethaneurea)of TDI can make the imPact strength raise by 5 l %, tensile strength raiseby 68%.The p o l yether-po ly(urethaneure as ) o f MDI c an make the imP actstrength improve by 70%,tensile strength improve by 45%.The addition3of poly(urethaneureas) makes the epoxy-resin curing reaction activation energy decrease by about 22%.