From your water bottle to the tyres on your car — the giant molecules that built the modern world. With interactive polymer identifier, monomer-polymer maps, and 25+ real-life examples.
Before diving in, here's the entire chapter on one page. How monomers → polymers → classification → applications.
Polymers = very large molecules formed by joining many small monomers. Addition polymerization (chain growth, no by-product) vs condensation polymerization (step growth, small molecule lost). Natural (proteins, cellulose, rubber), semi-synthetic (vulcanized rubber, cellulose acetate), and synthetic (PE, PVC, Nylon, Terylene, Bakelite). Vulcanization of rubber with sulfur improves strength. Biodegradable polymers (PHBV) are environmentally friendly.
Polymer: A very large molecule (macro molecule) formed by joining together many small repeating units called monomers. The process is called polymerization.
Monomer: The small molecule that repeats to form the polymer. Example: ethene → polyethylene.
Degree of polymerization: Number of monomer units in the polymer chain. Can be hundreds to thousands.
Example: n CH₂=CH₂ → [–CH₂–CH₂–]ₙ (polyethylene)
Natural polymers: Found in nature (in plants/animals)
Semi-synthetic polymers: Modified natural polymers
Synthetic polymers: Made entirely in the lab
Linear polymers: Long straight chains (with some side branches maybe).
Branched polymers: Chains with side branches.
Cross-linked (network) polymers: Chains connected by covalent bonds (cross-links).
Addition polymers: Formed by repeated addition of monomers (no byproduct). Monomers have C=C or C≡C.
Condensation polymers: Formed by condensation with loss of small molecule (H₂O, HCl, etc.). Monomers have two or more functional groups.
Elastomers: Weak intermolecular forces (Van der Waals), highly elastic, stretch and recover.
Fibers: Strong intermolecular forces (H-bonds, dipole-dipole). High tensile strength, less elastic.
Thermoplastics: Linear or branched chains (no cross-links). Soften on heating, harden on cooling — can be remolded.
Thermosetting plastics: Cross-linked networks. Cannot be remelted (decompose on heating). Rigid.
Polymers classified 4 ways: (1) By source — natural, semi-synthetic, synthetic. (2) By structure — linear, branched, cross-linked. (3) By polymerization mode — addition, condensation. (4) By molecular forces — elastomers, fibers, thermoplastics, thermosetting. Each classification has different property implications.
Definition: Monomers add together without losing any atom. Usually involves breaking C=C double bonds to form new C-C single bonds.
Key features:
Examples:
Mechanism (free radical):
Definition: Monomers join with loss of a small molecule (H₂O, HCl, NH₃, etc.). Usually involves two different monomers with reactive functional groups.
Key features:
Examples:
Copolymerization: Polymerization of two or more different monomers together. The resulting polymer is a copolymer.
Types of copolymers:
Examples of copolymers:
Addition polymerization (chain growth): monomers add, no byproduct, same formula as monomer — PE, PVC, Teflon. Condensation polymerization (step growth): two monomers, small molecule lost (H₂O, etc.) — Nylon, Terylene, Bakelite. Copolymerization: two or more different monomers — Buna-S, Buna-N, Nylon-6,6.
Polymers are not single molecules — they are a mixture of chains of different lengths (different molecular masses). So we calculate average molecular masses.
1. Number average molecular mass (M̄n):
M̄n = (Σ Nᵢ Mᵢ) / Σ Nᵢ
Where Nᵢ = number of molecules of mass Mᵢ. This is what colligative properties give (osmotic pressure, etc.).
2. Weight average molecular mass (M̄w):
M̄w = (Σ Nᵢ Mᵢ²) / (Σ Nᵢ Mᵢ)
This is what light scattering, ultracentrifugation, and sedimentation give. Higher because bigger chains contribute more.
Polydispersity index (PDI):
PDI = M̄w / M̄n
Degree of polymerization (DP or n): The number of repeating monomer units in one polymer molecule.
Formula: DP = (Molar mass of polymer) / (Molar mass of monomer)
Example: Polyethylene with M = 28,000 g/mol has DP = 28,000/28 = 1000 (1000 ethene units).
Typical DP values:
Enter polymer molecular mass and monomer molar mass → calculate DP.
Polymers have a distribution of chain lengths. M̄n (number average) — from colligative properties. M̄w (weight average) — from light scattering. PDI = M̄w/M̄n — measures polydispersity (ideal = 1). Degree of polymerization DP = M_polymer / M_monomer. Higher DP = higher strength, viscosity, melting point (usually).
| Polymer | Monomer | Type | Function |
|---|---|---|---|
| Proteins | α-Amino acids | Condensation | Structure, enzymes, hormones |
| Polysaccharides (starch, cellulose, glycogen) | Glucose | Condensation | Energy storage (starch, glycogen), structure (cellulose) |
| Nucleic acids (DNA, RNA) | Nucleotides | Condensation | Genetic information |
| Natural rubber | Isoprene (2-methyl-1,3-butadiene) | Addition | Elastic material |
Natural rubber: cis-1,4-polyisoprene. Comes from the latex of rubber trees (Hevea brasiliensis).
Structure: cis-polyisoprene — methyl groups on the same side of the C=C double bond. This cis-configuration is what gives rubber its elasticity.
Isoprene unit: –[CH₂–C(CH₃)=CH–CH₂]ₙ–
Properties:
Vulcanization: Raw rubber is heated with sulfur (2-3%) at 373-415 K, forming cross-links between polymer chains (S–S bonds). This:
Vulcanized rubber is used for tyres, hoses, gaskets, gloves.
Gutta-percha: Trans-polyisoprene (trans configuration) — hard, non-elastic (used for golf ball covers, insulation). Same monomer as rubber but different stereochemistry.
Natural polymers: proteins (amino acids), polysaccharides (glucose — starch, cellulose, glycogen), nucleic acids (nucleotides — DNA, RNA), natural rubber (isoprene). Natural rubber = cis-polyisoprene (elastic); gutta-percha = trans-polyisoprene (hard). Vulcanization = heating rubber with sulfur → cross-links → harder, stronger, more durable.
Choose a polymer — see its monomer, type, and uses.
| Polymer | Monomer(s) | Type | Use |
|---|---|---|---|
| Polyethylene (PE) | Ethene | Addition | Bags, bottles, containers |
| Polypropylene (PP) | Propene | Addition | Ropes, carpets, plastic parts |
| PVC | Vinyl chloride (chloroethene) | Addition | Pipes, cables, window frames, raincoats |
| Teflon (PTFE) | Tetrafluoroethene | Addition | Non-stick cookware, gaskets |
| Polystyrene (PS) | Styrene (phenylethene) | Addition | Packaging, cups, insulation |
| PMMA (Perspex) | Methyl methacrylate | Addition | Shatterproof glass, lenses, signs |
| Nylon-6,6 | Hexamethylenediamine + adipic acid | Condensation | Ropes, fabrics, parachutes |
| Nylon-6 | Caprolactam | Condensation | Tyres, textiles |
| Terylene (PET) | Ethylene glycol + terephthalic acid | Condensation | Polyester fabric, PET bottles |
| Bakelite | Phenol + formaldehyde | Condensation (cross-link) | Electrical switches, handles |
| Melamine | Melamine + formaldehyde | Condensation | Unbreakable plates, laminates |
| Elastomer | Monomers | Properties |
|---|---|---|
| Buna-S (SBR) | 1,3-Butadiene + Styrene | General purpose rubber, tyres |
| Buna-N (Nitrile rubber) | 1,3-Butadiene + Acrylonitrile | Oil-resistant, fuel hoses |
| Neoprene | Chloroprene (2-chloro-1,3-butadiene) | Chemical-resistant, wetsuits |
| Silicone rubber | Dimethyldichlorosilane + water | Heat-resistant, medical implants |
| Thiokol | Ethylene dichloride + sodium polysulfide | Solvent-resistant, seals |
Key synthetic polymers: PE (bags), PVC (pipes), Teflon (non-stick), PP (ropes), PS (packaging), PMMA (shatterproof glass). Condensation polymers: Nylon-6,6 (hexamethylenediamine + adipic acid), Terylene/PET (ethylene glycol + terephthalic acid), Bakelite (phenol + formaldehyde). Synthetic rubbers: Buna-S, Buna-N, Neoprene, silicone, thiokol.
Elastomers: Polymers with weak intermolecular forces (Van der Waals), highly elastic. Can stretch extensively and return to original shape. Chain segments are mobile due to low cross-linking (or none in raw rubber).
Examples: Natural rubber, Buna-S, Buna-N, neoprene, silicone rubber.
Natural rubber: Obtained from latex of rubber trees (Hevea brasiliensis). The monomer is isoprene (2-methyl-1,3-butadiene).
Structure: cis-1,4-polyisoprene. Methyl groups on the same side.
Raw rubber properties:
Vulcanization: Heating raw rubber with sulfur (2-3%) at 373-415 K for some time. Sulfur forms cross-links (S–S bonds) between chains at the allylic C-H bonds.
Effects of vulcanization:
Vulcanization was discovered by Charles Goodyear (1839) — accident when he dropped rubber + sulfur on a hot stove.
1. Buna-S (SBR — Styrene-Butadiene Rubber):
2. Buna-N (Nitrile rubber):
3. Neoprene (polychloroprene):
4. Silicone rubber:
5. Thiokol (polysulfide rubber):
Natural rubber = cis-1,4-polyisoprene (isoprene monomer). Vulcanization (sulfur cross-links) improves strength, durability, temperature resistance. Synthetic rubbers: Buna-S (tyres), Buna-N (oil-resistant), Neoprene (chemical/wetsuits), Silicone rubber (heat-resistant/medical), Thiokol (solvent-resistant/rocket).
Biodegradable polymers: Polymers that can be broken down by microorganisms (bacteria, fungi) in the environment into harmless products (CO₂, H₂O, biomass).
Why needed: Conventional polymers (PE, PVC, PS) are not biodegradable — they persist for centuries, causing plastic pollution in oceans, land, and food chains.
Examples:
Monomers: 3-hydroxybutanoic acid + 3-hydroxypentanoic acid (with valeric acid incorporated).
Synthesis: Produced by bacteria (Alcaligenes eutrophus) when grown on glucose + propionic acid. The copolymer (PHBV) is extracted from bacterial cells.
Properties:
Uses:
Limitation: Expensive compared to conventional plastics — limited to specialty applications.
Structure: Copolymer of glycine (H₂N-CH₂-COOH) and caprolactam (ε-aminocaproic acid derivative).
Synthesis: Condensation polymerization of glycine + caprolactam.
Properties: Biodegradable, good mechanical strength.
Uses: Medical implants (absorbable sutures), specialty packaging, environmental applications.
Monomer: Lactic acid (2-hydroxypropanoic acid), obtained from corn starch fermentation.
Properties: Biodegradable thermoplastic, compostable.
Uses: 3D printing filament, biodegradable packaging, food containers, medical implants (absorbable sutures, screws), disposable cups/cutlery.
A single plastic bag can take 500–1000 years to decompose. By contrast, biodegradable polymers like PHBV can break down in a few months in a compost environment. Switching to biodegradable polymers is a key strategy for reducing plastic pollution!
Biodegradable polymers: PHBV (from bacterial fermentation), Nylon-2-Nylon-6 (glycine + caprolactam), PLA (from lactic acid). Broken down by microorganisms into harmless products. Used for medical implants, biodegradable packaging, drug delivery. Key solution to plastic pollution.
"Addition ADDs, no byproduct" — same empirical formula as monomer (PE, PVC, Teflon)
"Condensation CONDENSeS, water lost" — different formula, byproduct (Nylon, Terylene)
"EFTT" — Elastomers, Fibers, Thermoplastics, Thermosetting
Increasing strength of intermolecular forces: Elastomer < Fiber < Thermoplastic < Thermoset (for rigidity)
"E-P-V-T-S" — Ethene (PE), Propene (PP), Vinyl chloride (PVC), Tetrafluoroethene (Teflon), Styrene (PS)
"H-A" — Hexamethylenediamine + Adipic acid
Both have 6 carbons each → Nylon-6,6
"Caprolactam → Nylon-6"
Ring-opening polymerization of caprolactam (6-carbon cyclic amide).
"EG + TA" — Ethylene Glycol + Terephthalic Acid
Polyester → PET bottles, polyester clothing
"P + F" — Phenol + Formaldehyde
First synthetic plastic (Baekeland, 1907). Thermosetting.
"Rubber is CIS, Gutta-percha is TRANS"
Both from isoprene. cis = elastic (rubber); trans = hard (gutta-percha).
"S for Strength"
Vulcanization uses sulfur (S) to cross-link rubber chains → stronger, more elastic, temperature-resistant.
"PHBV-PLA-N2N6"
PHBV, PLA, Nylon-2-Nylon-6 — the "eco-friendly" trio.
Use "Addition ADDs, Condensation CONDENSeS" for polymerization types. "H-A" for Nylon-6,6. "EG + TA" for Terylene. "S for Strength" for vulcanization. "CIS = Rubber (elastic), TRANS = gutta-percha (hard)".
Q1. Distinguish between addition and condensation polymerization.
Monomers add together with no loss of atoms. Same empirical formula as monomer. Involves C=C bond breaking. Examples: PE (from ethene), PVC (from vinyl chloride).
Monomers join with loss of small molecule (H₂O, HCl, NH₃). Different formula from monomer. Involves two different monomers with ≥2 functional groups. Examples: Nylon-6,6, Terylene, Bakelite.
Q2. What is vulcanization? What are its advantages?
Vulcanization is the process of heating raw natural rubber with sulfur (2-3%) at 373-415 K. Sulfur forms cross-links (S–S bonds) between polymer chains at the allylic C-H positions.
(1) Increases tensile strength
(2) Increases elasticity
(3) Makes rubber harder and more durable
(4) Improves temperature resistance (doesn't soften in summer)
(5) Reduces stickiness
(6) Less soluble in organic solvents
Discovered by Charles Goodyear (1839). Essential for tyres, hoses, industrial rubber products.
Q3. Write the monomers and uses of: (a) Nylon-6,6, (b) Terylene, (c) Bakelite.
Monomers: Hexamethylenediamine (H₂N-(CH₂)₆-NH₂) + Adipic acid (HOOC-(CH₂)₄-COOH)
Type: Polyamide (condensation)
Uses: Ropes, fabrics, carpets, parachutes, textile fibers. High strength due to H-bonds between amide groups.
Monomers: Ethylene glycol (HO-CH₂-CH₂-OH) + Terephthalic acid (HOOC-C₆H₄-COOH)
Type: Polyester (condensation)
Uses: Polyester fabrics (clothing), PET bottles, films, fibers. Recyclable.
Monomers: Phenol (C₆H₅OH) + Formaldehyde (HCHO)
Type: Cross-linked thermoset (condensation)
Uses: Electrical switches, handles, old telephone casings, adhesives, laminates. First synthetic plastic (Baekeland, 1907).
Q4. Discuss the classification of polymers based on molecular forces with examples.
Polymers can be classified by the strength of intermolecular forces: elastomers, fibers, thermoplastics, thermosetting plastics.
Weak intermolecular forces (Van der Waals). Highly elastic — can stretch extensively and recover shape. Chains are loosely cross-linked. Examples: Natural rubber (cis-polyisoprene), Buna-S, Buna-N, neoprene.
Strong intermolecular forces (H-bonds, dipole-dipole). High tensile strength, less elastic. Long thin threads. Examples: Nylon, Terylene, cotton, silk, wool.
Linear or branched chains, no cross-links. Soften on heating, harden on cooling — can be remolded repeatedly. Examples: PE, PVC, polystyrene, polypropylene, PMMA.
Cross-linked 3D network. Cannot be remelted (decompose on strong heating). Rigid, hard. Examples: Bakelite (phenol-formaldehyde), melamine-formaldehyde, urea-formaldehyde, epoxy resins.
Intermolecular force strength: Elastomer < Thermoplastic < Fiber < Thermoset (rigidity). Choice depends on application — elastomer for tyres, fiber for clothes, thermoplastic for containers, thermoset for electrical fittings.
Q5. (a) What are biodegradable polymers? (b) Why are they important? (c) Give two examples with monomers.
Biodegradable polymers are polymers that can be broken down by microorganisms (bacteria, fungi) in the environment into harmless products like CO₂, H₂O, and biomass.
Unlike conventional polymers (PE, PVC, PS) which persist for centuries, biodegradable polymers degrade in months to years.
(1) Reduces plastic pollution — conventional plastics harm oceans, land, wildlife.
(2) Reduced carbon footprint (often from renewable sources like corn, bacteria).
(3) Medical applications — absorbable sutures, implants (no need for second surgery).
(4) Compostable packaging (food industry).
(5) Addresses environmental concerns of single-use plastics.
Challenge: expensive compared to conventional plastics.
PHBV (Polyhydroxybutyrate-co-β-hydroxyvalerate):
Monomers: 3-hydroxybutanoic acid + 3-hydroxypentanoic acid
Produced by bacteria (Alcaligenes eutrophus). Used for biodegradable packaging, medical implants, controlled drug release.
Nylon-2-Nylon-6:
Monomers: Glycine (H₂N-CH₂-COOH) + Caprolactam
Synthesized by condensation polymerization. Used for biodegradable surgical sutures.
PLA (Polylactic Acid):
Monomer: Lactic acid (from corn starch fermentation)
Used for compostable food containers, 3D printing filament, medical implants.
Q6. (a) What is the difference between Buna-S and Buna-N? (b) Give their monomers and uses.
Buna-S and Buna-N are both copolymers of 1,3-butadiene, but they differ in the second monomer:
Buna-S: 1,3-butadiene + styrene (S from Styrene). Type: Styrene-Butadiene Rubber (SBR). General purpose rubber.
Buna-N: 1,3-butadiene + acrylonitrile (N from Nitrile). Type: Nitrile rubber. Oil-resistant rubber.
Monomers: 1,3-butadiene (75%) + styrene (25%)
Properties: good general-purpose rubber, better abrasion resistance than natural rubber
Uses: tyres (about 75% of synthetic rubber production), footwear, automotive parts, industrial hoses
Monomers: 1,3-butadiene + acrylonitrile
Properties: excellent oil and fuel resistance, good heat resistance
Uses: oil hoses, fuel tanks, gaskets, protective gloves, seals in automotive and aerospace industries
Selected exercise questions from the LEGACY NCERT Chapter 15 (Polymers). Useful for competitive exams.
Polymers: Very large molecules (macromolecules) formed by joining together many small repeating units called monomers through a process called polymerization.
Natural polymer: Protein (from amino acids), cellulose (from glucose), natural rubber (from isoprene).
Synthetic polymer: Polyethylene (from ethene), PVC (from vinyl chloride), Nylon-6,6 (from hexamethylenediamine + adipic acid).
(a) Nylon-6,6: Hexamethylenediamine + Adipic acid
(b) Buna-S: 1,3-Butadiene + Styrene
(c) Buna-N: 1,3-Butadiene + Acrylonitrile
(d) Terylene: Ethylene glycol + Terephthalic acid
(e) Bakelite: Phenol + Formaldehyde
Polymerization: The process by which small monomer molecules join together to form a large polymer molecule.
(a) Ethene → Polyethylene:
n CH₂=CH₂ → [–CH₂–CH₂–]ₙ
(b) Propene → Polypropylene:
n CH₂=CH-CH₃ → [–CH₂–CH(CH₃)–]ₙ
(c) Vinyl chloride → PVC:
n CH₂=CHCl → [–CH₂–CHCl–]ₙ
Homopolymer: Polymer formed from only one type of monomer. Examples: Polyethylene (from ethene only), PVC (from vinyl chloride only), Polypropylene (from propene only).
Copolymer: Polymer formed from two or more different types of monomers. Examples: Buna-S (butadiene + styrene), Buna-N (butadiene + acrylonitrile), Nylon-6,6 (hexamethylenediamine + adipic acid), Terylene (ethylene glycol + terephthalic acid).
Note: Copolymers often have properties that are combinations or improvements over homopolymers.
Vulcanization: Process of heating raw natural rubber with sulfur (2-3%) at 373-415 K. Sulfur forms cross-links (S–S bonds) between the polymer chains at the allylic C-H positions (allylic carbons are reactive).
Significance:
(1) Increases tensile strength
(2) Increases elasticity and resilience
(3) Makes rubber harder and more durable
(4) Improves temperature resistance (doesn't soften in summer, doesn't become brittle in winter)
(5) Reduces stickiness
(6) Reduces solubility in organic solvents
Vulcanized rubber is used in car tyres, hoses, industrial rubber products.
Biodegradable polymers: Polymers that can be decomposed by microorganisms (bacteria, fungi) in the environment into harmless products like CO₂, H₂O, and biomass. This solves the problem of non-biodegradable plastic pollution.
Examples:
(1) PHBV (Polyhydroxybutyrate-co-β-hydroxyvalerate): Produced by bacteria. Monomers: 3-hydroxybutanoic acid + 3-hydroxypentanoic acid. Used in biodegradable packaging, medical implants.
(2) Nylon-2-Nylon-6: Copolymer of glycine (H₂N-CH₂-COOH) + caprolactam. Used in biodegradable surgical sutures.
(Other examples: PLA — polylactic acid from lactic acid; PHA — polyhydroxyalkanoates.)
(a) Addition vs Condensation polymerization:
Addition: Chain growth. Monomers add (no byproduct). Same empirical formula as monomer. Monomer has C=C or C≡C. Fast. Examples: PE, PVC, Teflon.
Condensation: Step growth. Small molecule lost (H₂O, HCl, etc.). Different formula from monomers. Two different monomers with ≥2 functional groups. Slower. Examples: Nylon-6,6, Terylene, Bakelite.
(b) Natural vs Synthetic rubber:
Natural rubber: cis-1,4-polyisoprene (from latex of Hevea brasiliensis). Elastic, soft, sticky. Low tensile strength. Softens in summer, brittle in winter. Vulcanization improves properties.
Synthetic rubber: made in labs from petroleum monomers. Examples: Buna-S, Buna-N, neoprene, silicone. Can be designed for specific properties (oil resistance, heat resistance, etc.).
(a) Elastomer: Polymer with weak intermolecular forces (Van der Waals). Highly elastic — stretches extensively and returns to original shape. Chain segments mobile. Examples: Natural rubber, Buna-S, Buna-N, neoprene, silicone rubber.
(b) Fiber: Polymer with strong intermolecular forces (H-bonds, dipole-dipole). High tensile strength, less elastic. Long thin threads. Examples: Nylon, Terylene, cotton, silk, wool.
(c) Thermoplastic: Polymer with linear or branched chains (no cross-links). Softens on heating, hardens on cooling. Can be remolded repeatedly. Examples: PE, PVC, polystyrene, polypropylene.
(d) Thermosetting plastic: Polymer with 3D cross-linked network. Cannot be remelted (decompose on strong heating). Rigid, hard. Examples: Bakelite, melamine, urea-formaldehyde, epoxy.
Buna-S vs Natural Rubber:
Monomer:
• Buna-S: 1,3-butadiene (75%) + styrene (25%) — copolymer
• Natural rubber: isoprene — homopolymer (cis-1,4-polyisoprene)
Source:
• Buna-S: synthetic (petroleum-based)
• Natural rubber: natural (from latex of Hevea brasiliensis tree)
Properties:
• Buna-S: better abrasion resistance, heat resistance, oil resistance. Used in tyres primarily.
• Natural rubber: softer, more elastic. Needs vulcanization for strength.
Uses:
• Buna-S: tyres (75% of synthetic rubber), footwear, automotive
• Natural rubber: erasers, gloves, latex products
Teflon (PTFE — Polytetrafluoroethene):
Monomer: Tetrafluoroethene (CF₂=CF₂)
Polymerization: n CF₂=CF₂ → [–CF₂–CF₂–]ₙ (addition polymerization)
Structure: Carbon backbone with fluorine atoms attached to each carbon. Very strong C-F bonds.
Properties:
(1) Extremely chemically inert (resists acids, bases, solvents)
(2) Non-stick (very low surface energy)
(3) High melting point (~327°C)
(4) Excellent electrical insulator
(5) Low friction coefficient
Uses:
(1) Non-stick cookware (frying pans, baking trays)
(2) Gaskets and seals in chemical plants
(3) Electrical insulation (high-frequency cables)
(4) Laboratory equipment (chemically inert)
(5) Bearings and gears (low friction)
(6) Medical implants
Nylon-6:
Monomer: Caprolactam (6-carbon cyclic amide)
Synthesis: Ring-opening polymerization of caprolactam
Name: From caprolactam (6 carbon atoms)
Structure: –[NH-(CH₂)₅-CO]ₙ–
Nylon-6,6:
Monomers: Hexamethylenediamine (6 carbon atoms in diamine) + Adipic acid (6 carbon atoms in diacid)
Synthesis: Condensation polymerization
Name: From the two monomers — both have 6 carbons → "6,6"
Structure: –[NH-(CH₂)₆-NH-CO-(CH₂)₄-CO]ₙ–
General rule: For copolymers (2 monomers), the numbers refer to the carbon chain lengths of the monomers. For homopolymers (like nylon-6), the number is the carbon count in the single monomer.
| PE (polyethylene) | Ethene | Bags, bottles |
| PP (polypropylene) | Propene | Ropes, carpets |
| PVC | Vinyl chloride | Pipes, cables |
| Teflon (PTFE) | Tetrafluoroethene | Non-stick pans |
| PS (polystyrene) | Styrene | Packaging, cups |
| PMMA | Methyl methacrylate | Shatterproof glass |
| Nylon-6,6 | HMD + Adipic acid | Ropes, fabrics |
| Nylon-6 | Caprolactam | Tyres, textiles |
| Terylene (PET) | EG + Terephthalic acid | Polyester, PET bottles |
| Bakelite | Phenol + Formaldehyde | Electrical switches |
| Buna-S | Butadiene + Styrene | Tyres |
| Buna-N | Butadiene + Acrylonitrile | Oil hoses |
| Neoprene | Chloroprene | Wetsuits, gaskets |
| PE | Polyethylene |
| PP | Polypropylene |
| PVC | Polyvinyl chloride |
| PTFE | Polytetrafluoroethene (Teflon) |
| PS | Polystyrene |
| PMMA | Polymethyl methacrylate |
| PET | Polyethylene terephthalate (Terylene) |
| SBR | Styrene-butadiene rubber (Buna-S) |
| HMD | Hexamethylenediamine |
| DP | Degree of polymerization |
| PDI | Polydispersity index |
| PHBV | Polyhydroxybutyrate-co-hydroxyvalerate |
| PLA | Polylactic acid |
(A) Both true, R explains A. (B) Both true, R does NOT explain A. (C) A true, R false. (D) A false, R true.
All key facts at one place — perfect for competitive exams.