Preparation And Properties Of Epoxy-based Lightweight Buoyant Material

The ocean plays an increasingly important role in today’s society.In particular,the government’s further adjustment and clarification of the ocean strategy is becoming more and more demanding and applied to high-performance lightweight materials.However,at the present stage,foreign technology is far ahead of China in the field of buoyancy materials,and the ability to independently develop high-end buoyant materials plays an important role in China’s future development.Epoxy resin is one of the most important engineering polymers with good chemical resistance,excellent thermal,electrical insulation properties and high tensile strength,so it has a wide range of industrial applications.Mesoporous silica has significant advantages in terms of strength of the material compared to other inorganic fillers.Both hollow glass microspheres and polypropylene have lower density and superior strength.Therefore,the surface modified hollow glass microspheres and polypropylene were mixed with epoxy resin filled with mesoporous silica to explore the density and comprehensive properties of epoxy-based lightweight buoyancy materials.Experiments have shown that when the size of the material is close to the nanometer scale,its mechanical properties were greatly improved.Therefore,mesoporous silica was used to fill the epoxy resin to improve the mechanical properties of the material.We prepared mesoporous silica/epoxy composite material with different mesoporous silica contents.It has been found that the mechanical properties of the material increased firstly and then decreased as the filling ratio increases.Pure epoxy resin exhibits brittle failure,and epoxy resin exhibits ductile fracture after filling mesoporous silica.It has been found that mesoporous silica improves the toughness while increasing the strength of the material.Moreover,the transmission electron microscopy,infrared spectrum and nitrogen adsorption desorption curve of the composite materials indicate that the mechanical properties of the material were improved due to the adsorption of the epoxy resin at the pore edge of the mesoporous silica.At the same time,the epoxy resin had a good interfacial interaction with a small amount of templating agent remaining in the pores of the mesoporous silica,so that the mechanical properties were improved while having both strength and toughness.Hollow glass microspheres are widely used for the preparation of solid buoyancy materials because of their high strength and low density.In this paper,different coupling agents were used to react with hydroxyl groups on hollow glass microspheres to graft organic segment and functional groups with different structures on hollow glass microspheres.The hollow glass microspheres were modified by solvent method.By measuring the contact angle and surface element of the hollow glass microspheres,it was indicated that the organic segment on the coupling agent can be linked to the hollow glass microspheres by the solvent method.Scanning electron microscopy of the cross section of the composite material showed that the addition of mesoporous silica greatly improved the voids between the epoxy resin and the hollow glass microbeads.It can be seen from the cross section of the composite material that the surface of the unmodified hollow glass microspheres was smooth,and the surface of the modified glass microbeads was coated with epoxy resin.It shows that the modified glass microbeads were more firmly bonded to the resin,and there was almost no gap.The modified glass microbeads could greatly increase the adhesion of the hollow glass microbeads and the resin by intertwining the organic segments.Therefore,the tensile strength,bending strength,impact strength and other properties of the composite material had been improved.Polypropylene has low density,good strength and toughness.The most important thing is that polypropylene is cheap and has great competitive advantages in industrial manufacturing.Therefore,polypropylene,hollow glass microspheres,mesoporous silica and epoxy resin were combined to prepare buoyant materials.The compatibility of the inorganic particles with the epoxy resin was improved by modifying the hollow glass microspheres and the polypropylene.It was proved by thermogravimetry,surface element analysis and contact angle tested that the modified hollow glass microspheres and polypropylene surface were successfully grafted with polymer.The cross-section scanning electron microscopy and mechanical properties of the composite material were tested.It was found that compared with the modified polypropylene,the hollow glass microspheres accounted for a larger volume and are more in contact with the epoxy resin.So that hollow glass microspheres had the greatest influence on the mechanical properties of composite material.The effect of different content of polypropylene on the mechanical properties of composite material was also related to the volume of hollow glass microspheres and polypropylene.The composite material prepared by simultaneous modification of hollow glass microspheres and polypropylene had the most obvious improvement in tensile strength,impact strength and compressive strength.