A Novel Approach Toward Reactive Thermoplastic Prepregs Based on UV‐Initiated B‐Staging

The production of thermoplastic CFRPC semi‐finished products is energy‐ and time‐intensive due to the high melt viscosity of the polymer. This paper presents a novel reactive thermoplastic prepreg, made of a glass fiber fabric and a liquid acrylic resin (Elium C595E by Arkema). A photoinitiator is used for UV‐induced partial polymerization while maintaining the flowability of the resin, with a thermal initiator for full polymerization in hot pressing. In this study, the influence of photoinitiator content and temperature on polymerization behavior and thermal properties of the polymer was systematically studied and explained. In thermally induced polymerization, the T g of the polymer increases with higher processing temperatures. An increasing photoinitiator concentration leads to a higher reaction rate for pre‐polymerization, but results in a lower T g . Based on these results, an optimized resin formulation and processing parameters for the prepregs have been derived. Prepregs with varying pre‐polymerization have been produced and processed into multi‐layer laminates in hot pressing. Based on the novel prepregs, void‐free orthotropic glass fiber laminates with a T g of up to 106°C can be produced. Mechanical tests show a maximum flexural strength of 810 MPa and a flexural modulus of 27 GPa at a fiber volume content of 54%.