DEVELOPMENT OF POLYMER COMPOSITES FOR MITIGATION OF BLAST DYNAMIC EFFECTS

Abstract

The aim of the present work is to develop toughened epoxy composites, particularly for newlineretrofitting applications in the area of blast mitigation. The mechanical properties of newlineepoxy in the presence of three different classes of fillers; namely thermoplastics newline(polystyrene microspheres and polyethylene particulates), elastomeric fillers (PET newlineglycolysates and PET derived polyurethanes) and rigid particulates (Mesoporous silica newlineand Metal organic framework) were determined under different kind of loadings. The newlinemethodology adopted involved preparation of additives, characterization and evaluation newlineof the effect of their introduction on the mechanical, structural and thermal properties. newlineThe physico-chemical characteristics of the additives were established by techniques like newlineFTIR, particle size analysis, thermal analysis (TGA and DSC), PXRD, surface area newlineanalysis and Scanning Electron Microscopy (SEM). To aid the dispersion of the fillers newlinewithin the epoxy matrix, surface modification was attempted. Thermoplastic polystyrene newlinemicrospheres were first prepared by suspension polymerization of styrene monomer, newlinewhere the particle size was found to decrease with increasing stirring speed and newlinedecreasing feed concentration. The microspheres were nitrated and the resultant nitro newlinegroups were subsequently reduced to form amino-polystyrene. Determination of amine newlinecontent by acetylation technique revealed that ~8.1 % of the total nitrogen exists as free newlineamino groups in amino-polystyrene (APS), indicating that the remaining ~3.5 % exist as newlineunconverted nitro groups. newlineIn addition to polystyrene microspheres, the potential of polyethylene particulates newlinetowards epoxy toughening was also explored. For this purpose, LDPE films were newlineprepared by film blowing of the polymer in the presence of cobalt stearate based prov newlineoxidant (0.1 % w/w). The blown films (70 ± 5 and#956;) were subjected to thermo-oxidative newlineaging at 100 °C for 12 h, which resulted in oxidation of the polyethylene surface, leading newlineto its embrittlement.