Modification Of Epoxy Resin By Trace Graphene And Thermoplastic Resin

Graphene possesses extraordinary high specific surface area and young's modulus,which makes it possible for the preparation of epoxy resin based composites with excellent mechanical properties.It's an important and challenging project to disperse graphene flakes in epoxy resin homogeneously without secondary aggregation.In this paper,an in situ ball-milling method was proposed to make graphene disperse in epoxy resin with secondary exfoliation.To avoid aggregation,the employed content of graphene was set as low as parts per million(ppm).Finally trace graphene/epoxy resin nanocomposites which possess excellent homogeneity and adhesion were obtained.With the protection of epoxy resin,there won't be too many defects on the surface of graphene flakes during grinding,thus the high strength characteristics of graphene will be remained.In addition,the toughening effect of trace polyurethane and polycarbonate on epoxy resin was also investigated,respectively.Afterwards the better one was chosen as an appropriate modifier,and was employed for the modification of epoxy resin with the addition of graphene.(1)The results indicate that in situ mechanical grinding is an effective route to make graphene disperse well in matrix with second exfoliation.After being diluted,trace graphene/epoxy resin nanocomposites with good mechanical property were obtained.At 100 ppm,the young's modulus of as-prepared composites was optimal and can reach to 2835 MPa with an increase rate of 15.3%,which is consistent with theoretical calculation value.(2)In the second part,trace polyurethane/ epoxy resin and trace polycarbonate/epoxy composites were prepared successfully by the means of in situ polymerization method and solution blending method,respectively.The toughness of these two thermoplastic resins have been improved remarkably,and the toughening effect of polycarbonate is better.Ultimate impact strength was 19.81KJ/m~2,which is increased by 130.1%.(3)In this part,trace graphene as well as trace polycarbonate was dispersed in epoxy resin for the preparation of ternary composites with excellent integrated performances.100 ppm graphene/50 ppm polycarbonate/epoxy resin composites possess ultimate young's modulus as high as 3320 MPa,and the increase rate is 37.7%.While 100 ppm graphene/50 ppm polycarbonate/epoxy resin composites possess ultimate impact strength as high as 22.08KJ/m~2,which is increased by the rate of 144.8%.