One of the most used materials is plastic. Many things are made of plastic. Plastic bags, toys, bottles, car parts, eyeglasses, plastic cups, and cutlery are just a few of them.
In this lesson, we are going to learn about PLASTIC and we are going to find out the following:
Plastics are a group of materials, either synthetic or naturally occurring, that may be shaped when soft and then hardened to retain the given shape. This is done in conditions of moderate temperature and pressure.
Plastics are polymers (long chains of atoms bonded to each other). The vast majority of these polymers are formed from chains of carbon atoms, with or without the attachment of oxygen, nitrogen, or sulfur atoms.
Many things are made of plastics. It is because making them to the right shape is very easy.
The birth of the modern plastics era came in 1907, with the invention of Bakelite by the Belgian-born American Leo Baekeland. It is derived from fossil fuels. Before the invention of plastic, the only substances that could be molded were clays (pottery) and glass.
Plastics are made from natural materials such as cellulose, coal, natural gas, salt, and crude oil through a polymerization or polycondensation process.
Polymerization is a chemical process in which small molecules, called monomers, combine chemically into larger chain-like molecules that contain repeating structural units. The chain-like molecules are called polymers.
Polycondensation is a process when the chain-like molecules (polymers) are formed as a result of reactions involving the condensation of organic materials in which small molecules are split out.
The list can be a lot longer.
The following table contains the seven types of plastic and some common products that are made of each type.
1. Polyethylene Terephthalate (PET or PETE)
PET is a clear, strong, and lightweight plastic that is widely used. It is the most common thermoplastic polymer resin of the polyester family. This plastic is used to make many common household items, and it is generally considered a “safe" plastic. PET/PETE products can be recycled.
Common products:
2. High-Density Polyethylene (HDPE)
HDPE is a thermoplastic polymer produced from the monomer ethylene. It is commonly used petroleum thermoplastic for a wide range of applications. HDPE is commonly recycled.
Common products:
3. Polyvinyl Chloride (PVC)
PVC is the world's third most widely produced synthetic plastic polymer (after polyethylene and polypropylene). It is a high-strength thermoplastic material widely used in applications, such as pipes, medical devices, wire, and cable insulation. PVC contains dangerous chemical additives which can be toxic to health. PVC is a type of plastic that is not recyclable.
Common products:
4. Low-Density Polyethylene (LDPE)
Low-Density Polyethylene (LDPE) is a thermoplastic made from the monomer ethylene. This type of plastic is considered safe, but not accepted by recycling programs.
Common products:
5. Polypropylene (PP)
Polypropylene (PP), also known as polypropene, is a thermoplastic polymer used in a wide variety of applications. Polypropylene has excellent chemical resistance, is strong, and has the lowest density of the plastics used in packaging. This type of plastic is not generally recycled.
Common products:
6. Polystyrene (PS)
Polystyrene is a synthetic aromatic hydrocarbon polymer made from the monomer known as styrene. Polystyrene can be solid or foamed. Both forms can be recycled but are not generally recycled.
Common products:
7. Other plastic, refer to all other types of plastics.
Common products:
Plastic has advantages and disadvantages as well.
Some common plastic advantages are:
Some common plastic disadvantages are:
The environmental damage that plastic waste causes have become a global problem. Plastic can be very bad for the environment to the point that plastic pollution is possible.
Plastic pollution is the accumulation of plastic objects and particles (e.g. plastic bottles, bags) in the Earth's environment that adversely affects wildlife, wildlife habitat, and humans. The main reason for plastic pollution is negligence. It comes mainly from poorly recycled household waste, which is dumped in landfills or abandoned in nature.
Every year, billions of pounds of plastic end up in the world's oceans. Studies estimate there are now 15–51 trillion pieces of plastic in the world's oceans. Plastic in our oceans can arise from both land-based and marine sources.
Marine wildlife such as whales, fishes, seabirds turtles, ingest plastic waste from the water because they mistake plastic waste for prey. Most of them die of starvation as their stomachs are filled with plastic debris.
