Polymers practice · Mixed difficulty

Option B (Nylon-6,6) is correct because Nylon-6,6 is formed by the condensation polymerization of hexamethylene diamine and adipic acid.

Option C (SBR is called natural rubber) is wrong because SBR (Styrene-Butadiene Rubber) is a synthetic rubber, while natural rubber is polyisoprene.

Option B (Glyptal) is correct because glyptal polymers, which are polyesters of phthalic acid and glycerol, are commonly used in the manufacture of lacquers and paints due to their film-forming properties.

The correct answer is D (Assertion is wrong, but reason is correct statement) because branched polymers have lower tensile strength, and the intermolecular force of attraction is indeed less than that in linear polymers.

Option D (Nylon-66) is correct because Nylon-66 is a polyamide, meaning it contains nitrogen atoms in its repeating unit due to the amide linkages.

Option B (Hexamethylene and sebacic acid) is correct because Nylon-6,10 is a polymer formed from hexamethylenediamine and sebacic acid.

Option B is correct. Assertion is correct as the empirical formula of natural rubber is ${C}_5 {H}_8$. Reason is also correct as natural rubber contains no conjugative double bonds, but it's not the explanation for the empirical formula.

Option B (Isoprene) is correct because natural rubber is a polymer made up of isoprene units.

Option B (Proteins) is correct because peptide bonds are the characteristic linkages that join amino acids together to form proteins (polypeptides).

Option A (Thermoplastics) is correct because thermoplastics can be repeatedly softened by heating and hardened by cooling, allowing for repeated molding.

Option B (Terylene) is correct because Terylene (also known as Dacron) is a polyester polymer formed from ethylene glycol and dimethyl terephthalate.

Option C (Glycerol) is correct because glycerol can be nitrated to form glycerol trinitrate, also known as nitroglycerin, which is a powerful explosive.

Option D (Ethylene glycol and terephthalic acid) is correct because terylene (Dacron) is a polymer formed from the monomers ethylene glycol and terephthalic acid.

Option B ($cis$-isoprene) is correct because natural rubber is a polymer formed from the repeated units of cis-isoprene (2-methyl-1,3-butadiene).

Option B (Novalac) is correct because Novalac is a linear polymer formed by the reaction of phenol and formaldehyde, while Bakelite is a cross-linked polymer.

Option D (Nylon-6,10) is correct because Nylon-6,10 is formed by the condensation polymerization of hexamethylenediamine (6 carbons) and sebacic acid (10 carbons).

Option D (All statements are correct) is correct because Guttapercha is indeed trans-polyisoprene, it is a naturally occurring polymer, and it is known for being a relatively hard and resilient material.

Option B (Polymerisation) is correct because polymerization is defined as the union of molecules to form a larger aggregate without losing simple molecules.

Option B (Low density polythene) is correct because low-density polyethylene (LDPE) is produced through a free-radical polymerization process that results in significant chain branching.

Option B ($\left({C}_2 {H}_5\right)_3 {Al}+{TiCl}_4$) is correct because Ziegler-Natta catalysts are typically composed of a transition metal halide (like TiCl4) and an organometallic compound (like triethylaluminum).

Option C (isoprene and sulphur) is correct because vulcanization involves heating rubber (polymerized isoprene) with sulfur.

Option C (Adipic acid and hexamethylenediamine) is correct because nylon-66 is a polyamide formed by the condensation polymerization of adipic acid and hexamethylenediamine.

Option A ($\mathrm{C}{\mathrm{H}_2} = \mathrm{CHCI}$) is correct because Saran, a polymer of vinyl chloride, is used for making synthetic hair wigs.

Option D (Glyptal) is correct because Glyptal is a step-growth polymer, not a chain-growth polymer.

Option D (Bakelite) is correct because Bakelite is a thermosetting polymer formed from the condensation reaction of formaldehyde and phenol.

Option A (Rubber) is correct because rubber is a natural polymer, while Nylon-6, Nylon-6,6, and Nylon-6,10 are synthetic fibers.

The correct answer is D (Alkyd resin) because glyptal is a type of alkyd resin formed by the polymerization of phthalic acid and glycerol.

Option A is not true because low-density polythene is not tough; it is relatively flexible and has low tensile strength.

Option C (Regenerated fibre) is correct because rayon is made from cellulose that has been chemically processed and reformed.

Option B (Teflon-thermally stable cross linked polymer of phenol and formaldehyde) is not correctly matched because Teflon is a polymer of tetrafluoroethylene, while a cross-linked polymer of phenol and formaldehyde is Bakelite.