Last Updated: May 2026
NEET Chemistry Polymers 2027 — Class XII NCERT Chapter 15 — yields an average of 1-2 MCQs every year, with high-yield zones being addition vs condensation classification, monomer-polymer pairing, and biodegradable polymers. This guide covers the complete NCERT polymer notes, must-know monomer-product table, and 30 practice MCQs aligned to the NEET 2027 pattern.
Quick Facts: NEET Polymers 2027
| Aspect | Detail |
|---|---|
| NCERT chapter | Class XII Chemistry, Chapter 15 (Polymers) |
| Average NEET questions | 1-2 |
| Difficulty | Easy-Moderate |
| High-yield zone | Monomer-polymer pairs, biodegradable polymers |
| NEET 2025 question | Bakelite preparation reaction (formaldehyde + phenol) |
Classification of Polymers
By Source
- Natural: Cellulose, starch, proteins, natural rubber (cis-1,4-polyisoprene)
- Semi-synthetic: Cellulose acetate (rayon), nitrocellulose
- Synthetic: PE, PVC, Teflon, nylon, dacron
By Mechanism of Polymerisation
| Type | Example | Monomer |
|---|---|---|
| Addition (chain growth) | Polyethene, Teflon, PVC, polystyrene | Vinyl-type monomers |
| Condensation (step growth) | Nylon-6,6, dacron, bakelite, nylon-6, glyptal | Bifunctional monomers + small molecule loss (H₂O / NH₃) |
By Structure
- Linear: HDPE, PVC
- Branched: LDPE, glycogen, amylopectin
- Cross-linked: Bakelite, melamine, vulcanised rubber
By Molecular Forces
- Elastomers: Buna-S, Buna-N, neoprene — weak forces, stretchable
- Fibers: Nylon-6,6, dacron, terylene — strong H-bonds
- Thermoplastics: PE, PVC, polystyrene — soften on heat
- Thermosetting: Bakelite, urea-formaldehyde — set permanently after heating
Must-Know Monomer-Polymer Table (HIGH-YIELD)
| Polymer | Monomer(s) | Use |
|---|---|---|
| LDPE | Ethene | Squeeze bottles, plastic bags |
| HDPE | Ethene (Ziegler-Natta cat.) | Buckets, water tanks |
| PVC | Vinyl chloride | Pipes, raincoats |
| Teflon | Tetrafluoroethene | Non-stick cookware |
| Polystyrene | Styrene | Insulation, foam |
| Polyacrylonitrile (Orlon) | Acrylonitrile | Synthetic wool |
| Buna-S | 1,3-Butadiene + Styrene | Tyres |
| Buna-N | 1,3-Butadiene + Acrylonitrile | Oil-resistant rubber |
| Neoprene | Chloroprene (2-chloro-1,3-butadiene) | Wetsuits |
| Nylon-6,6 | Hexamethylenediamine + Adipic acid | Fabrics, ropes |
| Nylon-6 | Caprolactam (ring opening) | Tyre cords |
| Dacron / Terylene | Ethylene glycol + Terephthalic acid | Polyester fibers |
| Bakelite | Phenol + Formaldehyde | Switches, handles |
| Glyptal | Ethylene glycol + Phthalic acid | Paints |
| Melamine | Melamine + Formaldehyde | Unbreakable crockery |
Biodegradable Polymers (NEET-Favourite)
- PHBV (Poly-β-hydroxybutyrate-co-β-hydroxyvalerate): 3-hydroxybutyric acid + 3-hydroxypentanoic acid. Used as drug-release matrix and surgical implants.
- Nylon-2-Nylon-6: Glycine + Aminocaproic acid → completely biodegradable.
- Polyglycolic acid & Polylactic acid: Surgical sutures.
Natural Rubber and Vulcanisation
- Natural rubber = cis-1,4-polyisoprene (from Hevea brasiliensis).
- Gutta-percha = trans-1,4-polyisoprene (different geometry, hard).
- Vulcanisation: heating with sulphur (3-5%) → cross-links → enhanced strength/elasticity. Discovered by Charles Goodyear (1839).
Common NEET Trap Reminders
- Nylon-6,6: “6,6” indicates 6 carbons each in diamine + diacid.
- Nylon-6 is from a single 6-carbon monomer (caprolactam).
- PMMA (Plexiglas) = methyl methacrylate addition polymer (used in optic lenses).
- Polystyrene is addition; Bakelite is condensation — easy confusion.
- Buna-S vs Buna-N: ‘S’ = styrene; ‘N’ = nitrile (acrylonitrile).
FAQ — NEET Polymers 2027
Q1. Which polymer is used to make Teflon, and what is its monomer?
Teflon is polytetrafluoroethene (PTFE), made by addition polymerisation of tetrafluoroethene (CF₂=CF₂). Its high C-F bond strength gives it chemical inertness and non-stick property.
Q2. What is the difference between LDPE and HDPE?
LDPE is branched (free-radical polymerisation, high P/T) — flexible, used in bags. HDPE is linear (Ziegler-Natta catalysis) — rigid, used in buckets and tanks.
Q3. Is bakelite a thermoplastic or thermosetting polymer?
Bakelite is a thermosetting polymer made by condensation of phenol and formaldehyde, with cross-linking that prevents re-melting on heating.
Q4. What are PHBV polymers and why are they important?
PHBV is a biodegradable copolymer of 3-hydroxybutyric acid and 3-hydroxypentanoic acid. It is used in controlled drug-release devices and biodegradable packaging — a recurring NEET example.
Q5. Why is vulcanisation done?
Vulcanisation introduces sulphur cross-links between polyisoprene chains, increasing tensile strength, elasticity, and resistance to abrasion. Tyres are made of vulcanised Buna-S.
Practice MCQs
[cg_quiz id=”neet-chemistry-polymers-2027″]
Related Reading
- NEET Biomolecules 2027
- NEET Coordination Compounds 2027
- NEET Solutions 2027
- NEET 2027 Syllabus
- Free NEET Mock Test
Bottom line: Polymers is a “memorise-and-strike” topic for NEET 2027. Lock the monomer-polymer table and biodegradable examples — that’s two guaranteed marks.