EPOXY TOUGHENING WITH ORGANIC AND INORGANIC MODIFIERS FOR POTENTIAL USE AS BLAST MITIGATING RETROFITS

Abstract

In the wake of terrorist attacks, which usually take the form of small bombings, enormous attention has been directed towards development of materials which can be used for mitigation of blast effects. Explosive bombings usually result in damage to the nearby structural elements which hit the occupants of the buildings, leading to human injuries. To prevent the same, suitable multifunctional materials, which can be added as a retrofit layer on existing buildings, are the need of the hour. Although, thick steel panels are capable of providing the requisite level of protection, but in most cases, structures are not designed to support the additional weight requirements which these panels demand. In this project, we have attempted to improve the mechanical properties, in particular the energy absorption characteristics, of epoxy resins by the use of organic and inorganic fillers. The final intention is to use the developed composition as a retrofit layer on the existing unreinforced masonry (URM) structures. Concrete, a common component in all URM, exhibit high compressive strength, but its tensile strength is significantly low, and hence is usually reinforced with materials that are strong in tension (often steel). Retrofitting these structures with polymeric materials can improve the survivability of the walls in the event of a terrorist attack. These polymers can also serve as an additional layer in helmets which can prevent humans from traumatic brain injury. Epoxy resin was chosen as the base polymer and the effect of two different types of fillers on its mechanical properties have been investigated. Since the mixing of inorganic fillers is generally an issue, which necessitates the use of compatibilisers, we have attempted to develop mesoporous substrates, which can reduce the interfacial tension between the two phases. We hypothesized that these mesoporous silicates, due to their extremely high surface area, can lead to substantial improvement in the toughness even at low loadings, without compromising on the tensile strength. Organic modifier, namely amine terminated PEG was also employed as filler and the results are being reported