The Influence Of Surface Modification For Hollow Glass Microspheres On The Properties Of Epoxy Based Syntactic Foam

In the 21 st century,human exploration of the marine field has become an important part of economic development and cultural development.In the high-pressure deep-sea environment,the performance of exploration equipment is also facing a great test.As a new type of lightweight material,syntactic foam has gradually become a research hotspot.Among a wide variety of composite foam materials,the composite system with epoxy resin as the matrix and hollow glass microspheres as the filler is the most common.It has the characteristics of light weight,high strength,and good stability,it has been widely used in underwater equipment as filling material.However,the material properties and interface polarity of hollow glass microspheres and epoxy resin are quite different and they cannot be effectively combined.This defect will affect the mechanical properties of the material.Water-based sizing agent is a commonly used reagent in carbon fiber composite materials,which can effectively improve the interface bonding force between organic and inorganic materials and is quite environmentally friendly.Therefore,this paper uses water-based sizing agent to modify the surface of hollow glass microspheres and prepares epoxy-based composite foam materials.Then,the curing process of the composite material is explored and the surface modification of hollow glass beads,the performance of the composite foam material and the interface strength are discussed respectively:(1)In order to determine the appropriate curing process,different curing systems were analyzed using curing kinetics,the mechanism of the curing reaction was explored,and the effect of curing temperature and curing time on the curing conversion rate was analyzed(70 ℃,2 h;110 ℃,1h;170 ℃,1 h),and the appropriate curing condition was finally determined.(2)Use epoxy-based sizing agent and polyacrylate-based sizing agent to modify the surface of hollow glass microspheres,and determine that the modification is feasible by characterizing the surface morphology and molecular structure of the hollow glass beads before and after the surface modification.And determine the effect of sizing agent modification on the interfacial bonding force through the test of compressive strength.In addition,in order to determine the optimal amount of sizing agent,the improvement effect of different proportions of addition amount was explored.The results show that the compressive strength of the composite foam can be increased from 70.73 MPa to 89.03 MPa after sizing agent modification.(3)Dynamic mechanical properties of composite foam materials before and after modification of two sizing agents were tested by dynamic mechanical analyzer.,and the effects of temperature and frequency on the dynamic mechanical properties of the materials were respectively explored.The enhancement effect of the modification of the sizing agent on the dynamic mechanical properties of the syntactic foam is analyzed and the change of its glass transition temperature is explained.Finally,the density and thermal stability of the material are tested to ensure its practical application value.