Polymers and Plastics

Polytetrafluoroethylene (PTFE) has the glass transition temperature of 115 ^oC. The glass transition temperature of polyvinylidene fluoride or polyvinylidene difluoride (PVDF) is -35 ^oC. Polysulphone (PSF) has the glass transition temperature of 185 ^oC. The glass transition temperature of nylon-6 is 47 ^oC. Hence, the representation of codes A - 2, B - 1, C - 4, D - 3 is the correct answer.

P. Poly(methyl methacrylate) (PMMA) or perspex by brand name, is a transparent thermoplastic often used as a lightweight or shatter-resistant alternative to glass. Q. Rayon is a semi-synthetic polymer. It is made from purified cellulose, primarily from wood pulp, which is chemically converted into a soluble compound. It is then dissolved and forced through a spinneret to produce filaments which are chemically solidified, resulting in synthetic fibers of nearly pure cellulose. R. Celluloids are a class of compounds created from nitrocellulose and camphor, with added dyes and other agents. Generally considered the first thermoplastic, it was first created as Parkesine in 1856 and as xylonite in 1869, before being registered as celluloid in 1870. Celluloid is easily molded and shaped, and it was first widely used as an ivory replacement. The main purpose was movie and photography film industries. Hence, only statement R is the correct answer.

The usage of printing thickeners depends on the printing technique and fabric and dyestuff used. Typical thickening agents are- starch derivatives, Polyacrylamide (PAA), sodium alginate (SA). Albumen is both a thickening and a fixing agent for insoluble pigments such as chrome yellow. Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene having numerous applications such as low friction bearings, non-stick pans, anticorrosive coating materials etc. Hence, P, Q, R are used as thickening agents for textiles and papers.

Plasticizers or dispersants are additives that increase the plasticity or fluidity of a material. The dominant applications are for plastics, especially polyvinyl chloride (PVC). Examples are- Trimethyl trimellitate (TMTM), Dioctyl adipate (DOA), Dibutyl sebacate (DBS), Tricresyl phosphate (TCP) etc. Epoxy resins, also known as polyepoxides,  are a class of reactive prepolymers and polymers which contain epoxide groups. The applications for epoxy-based materials are extensive and include coatings, adhesives and resin matrices for composite materials. Examples are- Bisphenol F epoxy resin (BPFER), Novolac epoxy resin (NER). Hence, 1, 2 and 4 are the examples of plasticizers.

Safer plasticizers with better biodegradability and fewer biochemical effects are being developed. Some such plasticizers are- Trimethyl citrate (TMC) that are compatible with PVC, Acetyl tributyl citrate (ATBC), compatible with PVC and vinyl chloride copolymers etc. The examples of non-biodegradable plasticizers are- Butanetriol trinitrate (BTTN), Trimethylolethane trinitrate (TMETN) etc. Hence, P and Q both are examples of biodegradable plasticizers.

Polystyrene (PS) has good thermal insulator properties and is used in the making of moulded materials. Polyvinyl acetate (PVAc) is frequently used in adhesives. Polytetrafluoroethylene (PTFE) has very low coefficient of friction, excellent dielectric properties and chemical inertness. It is used mainly in the making of anticorrosive low friction bearings, non-stick pans, etc. Neoprene or polychloroprene is a family of synthetic rubbers that are produced by polymerisation of chloroprene. Neoprene exhibits good chemical stability and maintains flexibility over a wide temperature range. It is used in a wide variety of applications such as laptop sleeves, orthopedic braces (wrist, knee, etc), electrical insulation, liquid and sheet applied elastomeric membranes or flashings, and automotive fan belts. Hence, the correct answer using the codes is P - 2, Q - 4, R - 1, S - 3.

This option is correct because Dacron belongs to terylene unit of the polymers.

This option is correct.

Polycarbonates are transparent, self-extinguishing materials. They possess properties like crystalline thermoplasticity, high impact strength, good thermal and oxidative stability. They can be used in machinery, auto-industry and medical applications. For example, the cockpit canopy of F-22 Raptor is made of high optical quality polycarbonate.

A polyamide is a polymer containing monomers of amides joined by peptide bonds. They can occur both naturally and artificially, examples being proteins, wool and silk, and can be made artificially through step-growth polymerization or solid-phase synthesis, examples being nylons, aramids, and sodium poly(aspartate).

Styrene-Butadiene or Styrene-Butadiene-Rubber (SBR) is a synthetic rubber copolymer consisting of styrene and butadiene. It has good abrasion resistance and good aging stability when protected by additives, and is widely used in car tyres, where it may be blended with natural rubber.

Cross-linked polyethylene, is a form of polyethylene with cross-links. It is formed into tubing, and is used predominantly in hydronic radiant heating systems, domestic water piping and insulation for high tension (high voltage) electrical cables. It is also used for natural gas and offshore oil applications,  transportation of chemicals, and transportation of sewage and slurries.

Polyacrylonitrile (PAN) is a resinous, fibrous, or rubbery organic polymer. PAN fibres are the chemical precursor of high-quality carbon fibre. It is chemically modified to make the carbon fibres found in plenty of both high-tech and common daily applications such as civil and military aircrafts,  primary and secondary structures, missiles, solid propellant rocket motors, pressure vessels, fishing rods, tennis rackets, badminton rackets and high-tech bicycles.

Proanthocyanidin is a class of flavanols. Proanthocyanidins are essentially polymer chains of flavonoids such as catechins.

PVC stands for Poly Vinyl Chloride, a common synthetic plastic polymer used in pipes, cables, flooring, and many other applications. It is the third most widely produced synthetic plastic polymer in the world.