Thermal ageing studies of bromo-butyl rubber used in NBC personal protective equipment

Abstract

This study evaluates degradation and stability of bromo-butyl rubber (BBR) used in NBC personal protective equipment. Elongation increased by 10% when BBR was exposed to -65°C as well as 100°C. Tensile strength decreased by 50% when exposed to -65°C and also at 55°C, and decreased to around 63% when exposed to 80° and 100°C. Morphological appearance at 80°C aged sample was intact and comparable with unaged samples. BBR exposed to 120°C developed minor cracks (<0.01 µm). Life prediction was 89 and 25 years for exposed usage temperature of 40° and 50°C respectively. Since survival of personnel who don these equipments is involved the shelf life for equipments made of this particular formulation shall be safely considered at 50% of predicted life for respective temperatures.