The invention relates to a method for producing composite semi-finished products and components. In order to produce the semifinished products or components, (meth)acrylate monomers, (meth)acrylate polymers, multi-functionalized (meth)acrylates, hydroxy functionalized (meth)acrylate monomers, and/or hydroxy functionalized (meth)acrylate polymers are mixed with di- or poly isocyanates or uretdione materials. The liquid mixture is applied onto fiber materials, such as carbon fibers, glass fibers, or polymer fibers for example, using known methods and polymerized using a first temperature increase, a redox accelerator, or a photo-initiation. After the polymerization process, for example at room temperature or a temperature of up to 120 DEG C, thermoplastics are produced which can then still be deformed. The hydroxy functionalized (meth)acrylate components can then be crosslinked with the isocyanates or uretdiones which are already present in the system in a press at a second temperature which is at least 20 DEG C higher than the polymerization temperature. At the same time, the final component is shaped in said press. In this manner, dimensionally stable duroplastics or crosslinked composite components can be produced.