Physical and mechanical properties of nano-modified polybenzoxazine nanocomposite laminates: Pre-flight tests before exposure to low Earth orbit

Polybenzoxazine (PBZ) formulations based on commercial components and modified with polyhedral oligomeric silsesquioxanes (POSS, 5 wt% and 10 wt%) have been scaled up for industrialisation, and their processing characteristics determined using thermal analysis and rheometry. The ultimate glass transition temperatures for the cured PBZ resins are increased by catalysis and by the incorporation of POSS. Carbon fibre reinforced polymer (CFRP) laminates (500 mm × 500 mm x 3 mm) were manufactured using resin transfer moulding and subjected to a suite of mechanical tests. The addition of 5 wt% POSS to the PBZ formulation leads to substantial improvements in both strength (tensile, flexural, short beam shear, and compression) and modulus (tensile, flexural, and compression). The CFRP specimens were subjected to a suite of pre-flight qualification tests prior to deployment in low Earth orbit. When the CFRP laminates were exposed to