Plastic materials are widely used in construction and are indispensable building materials in modern buildings.
Plastics are divided into thermoplastics and thermosetting plastics. Within a specific temperature range, plastics that can be softened by heating, hardened by cold, and processed repeatedly are collectively referred to as thermoplastics, such as polyvinyl chloride, polyethylene, polypropylene, polystyrene, etc. Those that cannot be softened after being heated or cured under certain conditions are collectively referred to as thermosetting plastics, such as phenolic plastics, amino plastics, etc. Plastic can be processed into a variety of shapes and colors of products, processing methods are simple, high degree of automation, low production energy consumption. Therefore, plastic products have been widely used in industry, agriculture, construction and daily necessities. The commonly used molding methods for manufacturing building plastic products are: calendering, extrusion, injection, die casting, coating, lamination and so on. Plastic is light, is a good insulator of heat and electricity, and has strong resistance to chemical corrosion. When processing some plastics, the amount of plasticizers and reinforcers can be appropriately changed to obtain soft or hard products suitable for various uses. The elastic modulus of plastics is low, easy to produce deformation, thermal expansion coefficient is large, and fire resistance is poor, but it can be improved by strengthening, compounding and appropriate application measures. Some strength-to-weight ratios of glass fiber reinforced plastics are even higher than those of steel. Plastics are mostly used in construction as non-structural materials. Only a small part is used to manufacture structural components that bear light loads, such as plastic corrugated tiles, bus shelters, kiosks, water storage towers, inflatable structures, etc. However, it is more used in combination with other materials, which can give full play to the characteristics of plastics, such as being used as coated insulation materials for wires, veneer materials for wood-based panels, various composite wall panels with foam plastic sandwich layers, roof panels, etc. Therefore, building plastics are a kind of building materials with broad development prospects.
