Mechanical properties of EPS filled syntactic foams prepared by VARTM

Abstract

Abstract In this study, syntactic foams with honeycomb like structure were prepared with hollow glass microspheres (HGMs), epoxy resin, and expanded polystyrene (EPS) beads. A novel manufacturing approach of Vacuum Assisted Resin Transfer Mould (VARTM) was designed to avoid the effect of buoyancy on the EPS beads, due to the different densities of the raw materials. The EPS beads were served as sacrificial templates and shrank at high temperature, and thus produced hollow structure. EPS beads with four types of size were used. The average diameters are 0.75 mm, 1.50 mm, 2.50 mm and 4.00 mm, respectively. The foam density of the obtained syntactic foam can vary from 0.24 g/cm3 to 0.28 g/cm3. It was demonstrated by scanning electron microscope (SEM) that the EPS beads and HGMs could be dispersed uniformly in the resin system. Test results indicated that the resin permeating time, compressive strength, and syntactic foam densities presented an increasing tendency as the decrease of the EPS beads' diameters. Correspondingly, the average compressive strength enhanced from 3.6 MPa to 9.3 MPa. The resin permeating time increased from 6 min to 27 min with a thickness of 100 mm. In summary, this work provides an optimized way for the preparation of the low-density syntactic foams.