Plastic is an organic, synthetic polymer with many repeating structural units. Their properties depend on the chemical composition, crosslinking density and the presence of other organic additives. Plastics can be very different chemically and physically, but they all have one thing in common — their impermeability to water or air.
Plastic types and physical properties can differ widely, but they have one thing in common. They all have the same ability to resist water and air penetration. A plastic material’s permeability (or impermeability) is determined by its chemical structure.Most plastics are from oil and natural gas, abundant in the earth’s crust. Many plastics are used in packaging, to make household objects and furniture, and industrial applications.
7 Common Types Of Plastics
1. Acrylic or Polymethyl Methacrylate
It is a synthetic plastic with a high molecular weight. It is used for construction materials, ready-made food containers, etc. Virtually all polycarbonate plastic bottles are made from PMMA. Acrylic rubber called “Neoprene” is also made from PMMA. It is commonly used in automobile and truck tires and inner tubes.
2. Polyvinyl chloride
It is a synthetic polymer with a high molecular weight, used for manufacturing PVC floor tiles and for high-quality packaging of some products that need to be protected from the atmosphere, like films and photographic film.
3. PET(Polyethylene terephthalate) or PETE
PETE is not made from oil but is a petroleum derivative that, according to certain regulations, cannot be called plastic (it is not recycled). PET is made into either high-grade flexible bottles or rigid bottles.
Polystyrene is the best-known plastic thanks to its low cost, high impact strength and flame resistance. It is often used for disposable plastic products such as CD cases, egg trays, disposable cutlery and cups. Very useful for 3D printing. It has several derived types, such as rigid PS, HIPS, and XPS. It is also used for home insulation, food packaging, and other products.
5. EPS(Expanded polystyrene)
It is a non-plastic sheet form of polystyrene. It is an excellent insulating material and has good chemical resistance. Refrigeration cabinets, wall panels and furniture are made from EPS plastics.
Polylactic acid is a biodegradable thermoplastic aliphatic polyester derived from renewable resources, such as corn starch, tapioca roots, chips or sugarcane. It has several advantages over traditional petrochemical-derived plastic: it is biodegradable, compostable and photodegradable (it becomes brittle when exposed to sunlight).
PE is a ubiquitous and valuable plastic because of its low cost, flexibility, and strength. It is used to manufacture water pipes, indoor cables and hoses, garbage bags etc. It is soft but can be easily recycled because it does not contain hazardous substances such as chlorine or other halogens that could contaminate the environment in case of improper disposal or incineration.
Plastic is used for nearly all kinds of products. The only exception is the application of different plastics in areas that require materials with specific functions (including oxygen permeability). Although plastic should not be considered a substitute for non-plastic materials, no one can deny that it is a cheap and convenient resource that could save money and protect the environment.