Preparation And Synergistic Toughening Of Epoxy Resin/hollow Glass Beads Composites

Hollow glass bead (HGB) endows polymeric composites with many potentialapplications due to its special hollow structure and low density, which can be designedwith its shape and wall thickness. The low viscosity and different density for thecomponent of the composite system result in the float of HGB on the surface of the epoxyresin matrix during casting the epoxy/HGB composites with common method. And thusthe obtained materials become obvious two layers. It is limited to improve epoxytoughness for the addition of HGB. In this paper, on the one hand, the stepwise cureprocess from low-temperature to high-temperature was used to prepare epoxy/HGBcomposites after the organic montmorillonite (OMMT) was added into the system. On theother hand, we used carboxyl-terminated liquid butadiene-acrylonitrile rubber (CTBN)and HGB to toughen synergistically epoxy.We researched the effect of the loading of HGB on morphology, mechanical property,glass transition temperature, and density of composites. As a result，the high density ofHGB was more uniformly dispersed in epoxy matrix than the low density of HGB. Thetransition temperature of EP/HGB composite increased with increasing the volume ofHGB. With the increasing of the volume of S15, elastic modulus of composite reduced.The impact strength and flexural strength of composite increased first and then decreased.When the volume of S15reached14.3%, the impact strength and flexural strength ofcomposite had maximum values. When the volume of S60reached2%, the impactstrength, flexural strength and fracture toughness of the composite showed the bestmechanical properties. As we known, incorporation of CTBN would reduce compositesmodulus. However, When we mixed up HGB with composites, impact strength andfracture toughness improved. When the volume of S60reached1.7%, composite impactstrength had maximum value. And the impact strength of EP/HGB/CTBN composite washigher than that of EP/HGB composite.