Rheological modification of PET waste. Thermoplastic pultrusion as recycling technology

Abstract

Packaging sector generates 40% of the plastics consumption in Europe. Among Among the most consumed plastics Polyethylene terephthalate (PET) is still the material that undoubtedly continues to grow in the packaging sector. Because of that, there is a concern related to the recycling process, which today is only around 56%. This makes that at present, there are tons of thermoplastic material accumulated in landfills that could be a potential source of raw material (especially colored PET and multilayer). On the other hand, like PET waste (RPET), there are environmental problems associated with the disposal of composite materials in landfills, especially thermoset matrix composites. In this sense, due to the impossibility of recycling and reusing thermosetting composites, thermosets have composites are beginning to be replaced by thermoplastics. However, the main problem in the use of thermoplastic matrices in composite materials lies in the total impregnation of the reinforcement of the fiber due to the high viscosities of these materials. With the purpose of solving this limitation, and joining these needs, this work has been focused on obtaining new materials by modifying the less recyclable fractions of RPET. In this sense this material has been modified rheologically by reactive extrusion to replace thermosetting materials in the manufacture of composites, especially in thermoplastic pultrusion. From the first materials developed it has been possible to manufacture profiles from matrix 100% recycled material with adequate impregnation. The results of this study transform a waste into a product with high added value, reducing the carbon footprint and the costs of the process.