$word_{count}$: 250

Addition polymers (memorize monomer → polymer): CH2=CH2 → Polyethylene (PE). CH2=CHCl → PVC. CH2=CHC6H5 → Polystyrene (PS). CF2=CF2 → Teflon (PTFE). CH2=CHCN → Polyacrylonitrile $\frac{PAN}{Orlon}$. CH2=C(CH3)COOCH3 → PMMA (Plexiglass). CH2=CHOCOCH3 → Polyvinyl acetate (PVA). CH2=CCl-CH=CH2 → Neoprene. CH2=C(CH3)-CH=CH2 → Natural rubber (cis-1,4-polyisoprene). Condensation polymers (memorize monomer pair → polymer): Hexamethylenediamine + Adipic acid → Nylon-6,6 (polyamide). Caprolactam → Nylon-6 (ring-opening). Ethylene glycol + Terephthalic acid → Terylene/PET (polyester). Phenol + HCHO → Bakelite (phenol-formaldehyde). Melamine + HCHO → Melamine resin. Urea + HCHO → Urea-formaldehyde. Copolymers: Butadiene + Styrene → Buna-S (SBR). Butadiene + Acrylonitrile → Buna-N (NBR). Glycine + 6-aminocaproic acid → Nylon-2-nylon-6 (biodegradable). The naming convention helps: Nylon-6,6 = two monomers with 6C each. Nylon-6 = one monomer with 6C. PET = Poly Ethylene Terephthalate (monomers in the name). PTFE = Poly Tetra Fluoro Ethylene. JEE frequently shows a polymer structure and asks for the monomer(s), or vice versa.