Polymers and Plastics

Both thermosetting plastics and thermoplastics have almost the same tensile strength, durability and flexibility. The main difference between them is that thermosetting plastics once set cannot be moulded again, but thermoplastics can be remoulded on heating.

Non-stick coating on cookware should be made of such a material that neither reacts with oil nor allows the oil to stick over it. Teflon possesses both these properties. That is why it is used for coating cookware.

Teflon is non-reactive towards oil. Polythene and polystyrene melt down if they catch fire. Melamine is resistant to fire and is therefore known as a fireproof plastic.

Electric plugs, switches, etc. should be made of such materials, which neither allow the heat nor the current to pass through. Also, they should not melt down on heating. Thermosetting plastics possess these properties. Therefore, they are used for the same purpose.

Peptidoglycan, also known as murein, is a polymer consisting of sugars and amino acids that forms a mesh-like layer outside the plasma membrane of bacteria forming the cell wall. Peptidoglycan serves a structural role in the bacterial cell wall by giving structural strength as well as counteracting the osmotic pressure of the cytoplasm.

It is cement. On cement, the excise duty is levied at the rate of per tonne, i.e. according to weight. Hence, excise duty is charged according to the weight of cement, which comes under specific rate of duty.

Polymethyl methacrylate and Polyvinyl butyral: Both are amorphous polymers.

Polythene, PVC and DDT are third generation petrochemicals derived from ethylene, vinyl chloride and chlorobenzene, respectively.

Glycocalyx is an important component of biofilms. This structure helps the bacterial cell attach together and colonize. Through attachment, bacteria may grow on diverse surfaces such as rocks, in fast-moving streams, plant roots, and human teeth. Therefore, extracellular polymeric substance is a kind of glycocalyx that helps bacterial cells in a biofilm attach to their target environment to each other.

Statement 1 is correct. Nylon was the first synthetic fibre made from chemicals. It is a wrinkle resistant fibre. Statement 2 is also correct. High grade polyethylene is used to make bulletproof material.

Statement 1 is correct. Teflon is polytetrafluoroethylene, which is a waxy and an opaque material. It is employed as a coating on cooking utensils and in industrial applications. Statement 2 is also correct. Sodium hydroxide is a high alkaline chemical compound often used for cleaning products, water purification and the manufacture of paper products.

Rubber is soft and flexible, due to this it is used mostly in balloons, tyres and footballs.

Dacron and glyptal are polyesters. Dacron is a copolymer of ethylene glycol and terephthalic acid. Glyptal is a copolymer of ethylene glycol and phthalic acid.

PVC is the third-most widely produced synthetic plastic polymer. It is a polymer of vinyl chloride (CH₂ = CH- Cl).

 Plastic is a material consisting of any of synthetic or semi-synthetic organics that are malleable and can be molded into solid objects of diverse shapes. Plastics are typically organic polymers of high molecular mass, but they often contain other substances. They are usually synthetic, most commonly derived from petrochemicals, but many are partially natural.