Polyurethane

Advantages

Can be tailored chemically to yield products in a wide variety of forms.  Excellent abrasion resistance (elastomers) and tear resistance.  Resistant to ozone and aliphatic hydrocarbons.  May be injection moulded.  Excellent adhesion.

Disadvantages

Poor U.V. resistance. Isocyanates are highly toxic.  High smoke evolution.  Poor solvent and acid resistance. Limited heat resistance.  High hysteresis - hence heat build-up during cyclic loading.

Applications

Soft microcellular foams for cushioning, packaging.  Semi-rigid foams for insulation, foam-in-place buoyancy.  Hard microcellular foams for shoe soles, car bumpers, tyres, wheels, gears, fuel hose.  Structural foam for housings, panels.  Cast elastomers for bearings, gears and wheels.

NOTE: Polyether based PU is superior to Polyester-based PU in terms of resistance to hydrolysis, hysteresis, heat build-up and low temperature impact, but polyether PUs are inferior to Polyester PUs for oil and abrasion resistance, ageing and general mechanical props. 

 

Source : Abstracted from Plascams

For more information on Plascams please visit The Rubber and Plastics Research Association

 

Tell Us What You Think

Do you have a review, update or anything you would like to add to this article?

Leave your feedback
Submit