Plastics and composites are of great importance to today's society, as they are present in almost all areas of life and offer a wide range of benefits. In recent decades, there has been a notable rise in both the production and demand for plastics, leading to considerable environmental consequences. In the context of climate change and the concept of a circular economy, which prioritize recycling as the initial step before eventual thermal disposal at the end of a product's life cycle, there is a need for the development of optimized recycling strategies. The recycling of composites becomes challenging due to the combination of different polymers or the incorporation of fibers into the polymer matrix. One of the most promising approaches to recover glass or carbon fibers from composites is the pyrolysis. In this process, the polymer matrix is decomposed at high temperatures under inert conditions, producing (fiber-containing) solid residues, liquids and gaseous products. Pyrolysis of polymers and composites can result in the release of fiber-containing aerosols or organic pollutants that affect human health. Therefore, comprehensive characterization of the pyrolysis process at the molecular level is of great importance. The identification of molecules formed during pyrolysis can be achieved by coupling thermal analysis with Fourier transform ion cyclotron resonance mass spectrometry (TA FT-ICR MS). [1,4]

A better understanding of pyrolysis processes also enables the development of optimized recycling strategies and can support the effective expansion of a circular economy. Thermal analysis techniques, such as thermogravimetric analysis (TGA), can be used to simulate the pyrolysis at laboratory scale, providing information on the thermal behavior of materials to enable adjustments to actual reaction conditions. [1,3]

Composites are predominantly recognized today as fiber-reinforced plastics, where fibers are incorporated within a polymeric, mineral, or metallic matrix. A variety of fiber types, including glass-, carbon-, boron-, HDPE-, silicon carbide-, aramid- and natural fibers, are used for such composite materials. Each fiber type offers unique properties and advantages that make it suitable for different applications. [1,2] Carbon fibers are of utmost significance in composites utilized in sectors including aerospace engineering, medicine, and renewable energy. Nonetheless, the existing production process of carbon fibers, primarily reliant on polyacrylonitrile, results in considerable greenhouse gas emissions and high expenses. Utilizing asphaltenes as a feedstock for carbon fiber manufacturing has the potential to cut costs by up to 90 % and offer alternative material-technological applications for extra-heavy fossil fuels. [3]