Research On High Performance Attapulgite Reinforced Polymer Matrix Composites

The research area of polymer/clay nanocomposites has attracted a great deal ofattention over the last two decades. Outstanding improvements in physical properties ofpolymeric matrices (e.g. stiffness, strength, heat distortion temperature, reducedpermeability to gas and liquids, fire retardancy), can be expected with only few weightpercents of clay, therefore promising to eliminate the typical compromise betweenproperties and processability of composite materials. Attapulgite, fibrous filler, is ahydrated magnesium aluminum silicate with very high surface area, formed by twotetrahedral silica sheets enclosing a central sheet of octahedral magnesia. Attapulgitehas great potential to become novel reinforced filler.Epoxy acrylate (EA) resin is the classic resin for UV curing coatings because of itsgood integrated performance such as outstanding adhesion, non-yellowing, flexibility,hardness and chemical resistance, and thus wide applications. These desirable propertiesof EA resin are partially negated by its relatively high viscosity under ambientpolymerization conditions. Bismaleimide resin is known to be the representative ofthermally resistant thermosetting resins, showing outstanding integrated performanceand thus great potential applications in many cutting-edge fields. However, achievingsignificant improvements in toughness of both EA and BMI resins remains challenging.Novel high performance UV-curable coatings based on epoxy acrylate (EA)oligomer and hyperbranched polysiloxane (HPSi) were prepared, the effect of HPSi onthe processing of uncured EA/HPSi system and integrated performance of cured resinswas evaluated. Results showed that a small addition of HPSi could greatly decrease theviscosity of EA oliogmer, while the viscosity almost did not reduce as the content ofHPSi continuously increased owing to the interaction between HPSi and EA oliogmer.The integrated performance of cured resins was closely related with the content of HPSi,and those resins with suitable contents of HPSi had significantly improved toughness and stiffness as well as thermal and moisture resistance.HPSi was used to modify attapulgite through “graft to” method. This modificationfacilitated dispersal of attapulgite in organic phases and allowed epoxy acrylatenetworks to link to the ATT surface. The effects of interfacial structure on themechanical and thermal properties of the modified reinforced EA resin matrix compsitewere discussed. Results showed that compared to the montmorillonite, the mechanicalreinforcement of attapulgite was more marked.Bismaleimide nanocomposites containing rod-like silicate (attapulgite) wereprepared using a simple organic modification to the nanorods. The modification led toeffective interfacial adhesion between the ceramic nanorods and the bismaleimide resinand hence good load transfer. The effects of organoclays on the curing reactions in thebismaleimide system at low temperatures (ene reaction) and hightemperatures(Diels–Alder reaction, homopolymerization of bismaleimide, and alternativecopolymerization) were investigated with differential scanning calorimetry. Theattapulgite modified bismaleimide/diallylbisphenol A system had excellent stiffness andtoughness with small amount of modified attapulgite.Attapulgite reinforced epoxy acrylate and bismaleimide resin matrix compositesare high-performance which can be served as high-performance electronic packagingmaterials, adhesives, biomaterials, coatings and so on, exhibiting great potentical inmany cutting-edges fields including aerospace, electronic information technologies andmedical field.