Bromo-butyl Rubber for Face Piece of a Respiratory Mask

Respiratory mask contains a number of components made of materials like rubber, plastics, and metals. Out of all the components, face piece is the main component exposed to the external environment. This study aims to evaluate degradation of bromo-butyl rubber. The experiments were carried out for thermal exposure, swelling study, saline exposure, etc. It is observed that the elongation at break was increased by 10 per cent when these were exposed to 100 oC. However, the tensile strength has been observed to decrease by 50 per cent when exposed to 55 oC. It is decreased to around 63 per cent when exposed to 80 oC and 100 oC. The morphological appearance of unaged sample was intact. Only samples at 120 oC aged for 48 h appeared to have developed minor cracks of <0.01 µm. There were no significant changes observed when the samples were exposed to saline (3 % NaCl) and artificial sweat solution.Defence Science Journal, 2009, 59(5), pp.505-511, DOI:http://dx.doi.org/10.14429/dsj.59.155

Studies of benzene adsorption using response surface methodology

257-265Benzene removal efficiency of granular activated carbon in indoor/poorly ventilated rooms has been studied. Commercially available coconut shell based granular activated carbon is used for this purpose. The benzene removal efficiency of carbon dosage of 50-100mg and benzene concentrations of 3-12 µg at environmental parameters, viz. temperature (25-45ºC) and pressure (10-100 mbar) has been studied. Response surface methodology is used for the optimization of environmental parameters. The maximum percentage removal of 45-48 is achieved at 35ºC. It shows that the physisorption plays main role in benzene removal. The samples are analysed using GC