Plastics are currently indispensable for the production of construction materials, electric insulation, drinks and food packaging, textiles and many more applications. Unfortunately, the mass production of synthetic polymers, especially for packaging materials, has led to an enormous waste problem for the environment. The polymers polyurethane and polyvinyl alcohol contribute to approximately 8 percent of the European plastic production. For several years methods to achieve an environmentally-friendly recycling of plastics have been the subject of intense investigations. This would not only relieve the environment, but also reduce the amount of petrol required to make new plastics chemically. Furthermore, less of the greenhouse gas CO2 would be emitted by garbage incineration plants that currently burn plastic waste.