This thesis investigates matrix microcracking behaviour in thermoplastic composites at various temperatures, with a focus on Toray Cetex TC1225, a high-performance thermoplastic composite material reinforced with carbon fibres. The research examines the feasibility of using room temperature data to predict low-temperature performance, to minimize the need for extensive cryogenic testing. Both experimental and analytical methods are used to assess how mechanical properties and residual stresses influence microcracking. Comprehensive testing at room and low temperatures (-65°C) was conducted, with the resulting correlations analysed in detail. The findings of this study contribute to the development of more reliable cryogenic storage solutions, particularly