Compared with other materials, plastic has the following performance characteristics:
1. Lightweight
Plastic is a lighter material with a relative density distribution between 0.90-2.2. It is obvious whether plastic can float to the water surface, especially foam plastic, which has micropores and a lighter texture, with a relative density of only 0.01. This characteristic allows plastics to be used in the production of products that require weight reduction.
2. Excellent chemical stability
The vast majority of plastics have good corrosion resistance to chemicals such as acids and alkalis. Especially polytetrafluoroethylene (F4), commonly known as the plastic king, has chemical stability even better than gold and will not spoil even after being boiled in "aqua regia" for more than ten hours. Due to its excellent chemical stability, F4 is an ideal corrosion-resistant material. F4 can be used as a material for transporting corrosive and viscous liquids in pipelines.
3. Excellent electrical insulation performance
Ordinary plastic is a poor conductor of electricity, with a large surface resistance and volume resistance, which can reach 109-1018 ohms in numerical terms. The breakdown voltage is high, and the tangent value of the dielectric loss angle is very small. Therefore, plastics have a wide range of applications in the electronic and mechanical industries. For example, plastic insulated control cables.
4. Poor conductors with heat insulation and shock absorption effects
Generally speaking, the thermal conductivity of plastics is relatively low, equivalent to 1/75-1/225 of steel, and the micropores of foamed plastics.
It contains gases and has better insulation, sound insulation, and shock resistance. The thermal conductivity of polyvinyl chloride (PVC) is only 1/357 of that of steel and 1/1250 of that of aluminum. In terms of insulation capacity, single glass plastic windows are 40% higher than single glass aluminum windows, and double glass windows are 50% higher. After combining plastic windows with insulating glass, it can be used in residential buildings, office buildings, wards, and hotels, saving heating in winter and air conditioning expenses in summer. The benefits are very obvious.
5. Wide distribution of mechanical strength and high specific strength
Some plastics are as hard as stone or steel, while others are as soft as paper or leather; From the perspective of mechanical properties such as hardness, tensile strength, elongation, and impact strength of plastics, there is a wide range of distribution and a wide range of options for use. Due to its small specific gravity and high strength, plastic has a high specific strength. Compared with other materials, plastics also have obvious drawbacks, such as easy combustion, lower stiffness than metals, poor aging resistance, and heat resistance.
Article source: excerpts from Baidu Baike
