Investigation of the corrosive enviroment effects on ageing of aluminium and hydroxy-terminated polybutadiene (HTPB) based composite materials

Aluminum (Al) and Hyroxyl-Terminated Polybutadiene (HTPB) are most common ingredients for composite rocket propellants. In this study, various ratios of Al and HTPB ageing with time in composite materials were investigated. For this purpose, composite samples were prepared at different HTPB /Al ratios (HTPB / Al: 4.44, 2.77, 1.88, 1.33). Then, they were aged at 90 ?C for 22 days in the oven under humidity and oxygen atmosphere. While the effects of aging on the corrosion behavior of the composite materials were investigated by using Tafel extrapolation method in 0.1 M HCl aqueous solution at 25 ±0,1 0C, the microstructure was investigated by XRD analyses . The results showed that oxide layer of aluminum on the surface of the sample was passive at the beginning, but after five years, the oxide layer was opened and aluminum started to be activated. After ten years ageing time, it was determined that oxide layer was formed again and the surface was become passive. Active-passive transitions on the surface during ageing were identified by XRD and Tafel Extrapolation methods followed each other.In addition to this, again under humidity and oxygen atmosphere, samples were aged in a microcalorimetry system at 90 ?C for 22 days and the heat flow per unit time were investigated. The increment of the effects of corrosive enviroment was determined in order of OxygenKeyword: Alüminyum = Aluminum ; Hidroksi üç gruplu polibütadien = Hydroxy terminated polybutadiene