Beginner Topic 1027 of 1102 Biochemistry, Environment & Industry

Plastics

Synthetic polymers shaped by heat and pressure.

Practise Biochemistry, Environment & Industry All Biochemistry, Environment & Industry topics

In-depth explanation of Plastics

Plastics are synthetic polymers, typically made from petrochemical monomers, that can be moulded into shape under heat and pressure. Many commercial plastics contain additives such as plasticisers that soften them, stabilisers that resist UV light or heat, and colourants. Their durability, lightness and low cost make them useful in packaging, construction and medicine, but the same persistence causes waste to accumulate in the environment. Global plastic production is now around 400 million tonnes per year. Plastics are classified by how they behave on heating, as thermoplastics or thermosets.

Going deeper: Plastics

Key ideas: Synthetic polymers shaped by heat or pressure, made by addition polymerization (alkenes, chain growth) or condensation polymerization (step growth, losing small molecules such as water). Properties depend on chain length, branching, crosslinking and crystallinity. Resin identification codes 1 to 7 label types. Most come from petroleum feedstock like ethylene and propylene.

Common mistakes and connections: Students assume all plastics are non-recyclable or all biodegradable; bioplastics are not necessarily biodegradable and oil-based ones are not either. Plastic is not a single material. Links to polymer chemistry, recycling and microplastics.

Visualization of Plastics

Approximate share of global plastic production by polymer. Polyethylene and polypropylene dominate the roughly 400 million tonnes made each year. The interactive lesson shows this as a live animation or chart.

Worked example and use case

PET bottles are made from a polyester plastic that is widely used for drinks.

Frequently asked questions about Plastics

What is Plastics?

Synthetic polymers shaped by heat and pressure.

Is Plastics a beginner, intermediate or advanced topic?

Plastics is a beginner topic in Biochemistry, Environment & Industry. It needs no earlier chemistry lessons and is a good starting point.

What should I learn before Plastics?

Study these earlier topics in Biochemistry, Environment & Industry first: Maillard Reaction, Chemistry of Cooking, Cosmetic Chemistry.

What comes after Plastics?

The next topics in Biochemistry, Environment & Industry are Thermoplastics and Thermosets and Polyethylene.

Can I practise Plastics with quizzes?

Yes. The interactive lesson includes a self-check question on Plastics, and the Biochemistry, Environment & Industry quiz draws on every topic in this area.

Where Plastics fits in Biochemistry, Environment & Industry

Plastics is topic 52 of 127 in Biochemistry, Environment & Industry.