Plastic Waste as a Resource, its Availability, and the Conversion Technologies for its Transformation to Wealth in the form of Thermal Insulating Materials

Plastics are one of the most significant technological achievements of the twentieth century due to their versatile nature, sizable lifetime, lightweight, low price, resistance to corrosion, low toxicity, resilience, and economic built-up budget. Therefore, polymer-based plastic products are extensively used in packaging, building, construction, agriculture, the medical industry, and many other fields. However, due to the enormous production and ineffective recycling methods of plastics, a significant amount of plastic waste is piling up and polluting our environment. Therefore, it is essential to devise a two-fold (cost-effective and eco-friendly) method to utilize such tremendous plastic waste. Plastic has a characteristic property of poorly transforming heat so that it can be easily transformed into thermal insulating materials. For this, mechanical recycling is a proven methodology comprising mechanical operations like dust-removing, shredding, washing, drying, densifying, agglomerating, and extrusion. Compared to conventional thermal insulation materials, recycled plastics provide several benefits, including ease of accessibility, cheap cost, low thermal conductivity, low density, weak water absorption, and a long lifespan. This chapter focuses on an overview of plastic wastes, including their availability, usage as resources, different technologies for turning them into valuable goods, and waste plastics as thermal insulating materials.