Terylene

Summary: Terylene is the trade name for PET polyester when used as a textile fibre. It is a condensation polymer made from ethane-1,2-diol and benzene-1,4-dicarboxylic acid. Used for clothing due to its strength, crease resistance, and quick-drying properties. Tags: igcse chemistry organic-chem polymers polyester Created: 2026-07-14 Last Updated: 2026-07-23


What Is Terylene?

Terylene is the fibre form of PET (polyethylene terephthalate) — a condensation polyester. Chemically identical to PET, Terylene is the brand name used when the polymer is extruded into fine fibres for textile use. In the US, it is known as Dacron.

Formation

See PET for the full chemical detail.

Terylene is made by condensation polymerisation of:

  • Ethane-1,2-diol (HO—CH₂—CH₂—OH) — a diol
  • Benzene-1,4-dicarboxylic acid (HOOC—C₆H₄—COOH) — a dicarboxylic acid

Each ester linkage formed eliminates one molecule of water.

How Terylene Fibres Are Made

  1. PET polymer is synthesised by condensation polymerisation
  2. The molten PET is extruded through tiny holes in a spinneret
  3. The thin streams cool and solidify into continuous filaments
  4. The filaments are drawn (stretched) to align the polymer chains → increases strength
  5. The fibres are twisted together to form yarn
  6. The yarn is woven or knitted into fabric

Properties

PropertyDescriptionReason
StrongHigh tensile strengthAligned polymer chains in drawn fibres
Crease-resistantDoes not wrinkle easilyPolymer chains spring back to original shape
Quick-dryingDoes not absorb much waterNon-polar regions, mostly hydrophobic
LightweightLow densityOrganic polymer
ElasticStretches and recoversChains can extend slightly and recoil
Abrasion resistantDoes not wear out quicklyStrong covalent bonds in backbone
ThermoplasticSoftens when heatedCan be heat-set into pleats/creases
Moth and mildew resistantNot attacked by insects/fungiNot a natural fibre
ColourfastHolds dye wellDyes can be incorporated during extrusion

Everyday Uses

UseProperties Exploited
Clothing (shirts, suits, dresses)Crease-resistant, durable, colourfast
Sportswear / activewearLightweight, quick-drying, wicks moisture
Fleece jacketsLightweight, warm (traps air), quick-drying
Curtains and upholsteryCrease-resistant, durable, colourfast
CarpetsAbrasion resistant, stain resistant
Sleeping bags (hollow fibre filling)Lightweight, insulating, compressible
Sewing threadStrong, colourfast, does not rot
Blended fabrics (polyester-cotton)Combines comfort of cotton with durability of polyester

Terylene Blends

Terylene is often blended with natural fibres:

  • Polyester-Cotton (Polycotton): Cotton for comfort/breathability + polyester for durability/crease resistance
  • Polyester-Wool: Wool for warmth + polyester for shape retention

Terylene vs PET

PETTerylene
Same polymer?YesYes
FormMoulded plastic (bottles)Extruded fibre (textile)
ProcessingInjection/blow mouldedSpun through spinneret
AppearanceClear/transparentOpaque fibre
UsesBottles, containersClothing, furnishing

Key Facts

  • Terylene = PET in fibre form — chemically identical
  • Made by condensation polymerisation (diol + dicarboxylic acid → polyester + H₂O)
  • Contains ester linkages (−COO−) in the polymer backbone
  • Crease-resistant — key advantage over natural fibres like cotton
  • Quick-drying — does not absorb much water
  • Thermoplastic — can be heat-set (e.g. permanent pleats)
  • Often blended with cotton to make polycotton
  • Brand name is Terylene (UK) or Dacron (US)