Cold Cure Elastomers

 
 
Food Chute lining, grain buckets.
 
Mining & Quarrying Bunker lines, conveyor rollers, scraper blades, flotation cell impellers, pump linings, grading screens, lined pipe, cross-over pads.
Oil, Chemical & Marine Bushings, bearings, hydrocyclones, buoys, pipeline pigs and scrapers, fenders, valve seats.
Rollers Board rollers, nip rollers, metal forming, printing, conveyor, can coating, paper mill.
 
Seals & Gaskets Pneumatic and oil seals, diaphragms.
Shoe Industry Shoe soles, bottom molding diaphragms, wear plates, energy-absorbing insoles.
 
Wheel & Tires Pallet truck tires, heavy duty caster wheels

Automotive Body panels, grommets, bearings, bushes, flexible couplings.
Building and Construction Moulds for concrete, gate seals, mastic shuttering. 
Coated Fabrics Conveyor belts, fuel storage tanks, power transmission belts, fabric-backed sheeting.
Electrical Encapsulation, insulation, potting, cable jointing.
Engineered Components Gears, sprockets, wire guides, rail draft gear, stripper plates, press plates, press brake pads, textile yarn guides, cutting boards, business machine belts.

APPLICATIONS
Superior cost-performance has led to many instances of replacing metals, rubber, wood and plastic with polyurethane elastomers.  Some of the applications of polyurethane are shown in the following table.

MDI - Advantages Disadvantage
Very good physical properties when well formulated Benzene rings cause discouloration of clear materials, but not loss of physical properties provided correctly pigmented
Reasonable cost materials available in many different forms.  Hence, now able to have materials that do not tend to 'crystallise' Pure forms give better properties but crystalisation under winter conditions
Good shelf life Reacts with atmosphere moisture even though it contains no caralyst
Viscosity can be tailored to the application  
   

MDI

 
Polyesters
 Original technology used in urethane technology
 General now used in selected applications
 
Advantages Disadvantage
Good solvent resistance Generally higher visicosities
Good physical properties, often 10-20% better than polyethers Poor hydrolytical stability
Better high temperature properties particularly compression set at 70?C Poor with even weak acids and bases
  Poor weatherability

Advantages Disadvantage
Relative low cost Poor properties at higher temp above 90?C
Manufactured in volume, 90% market hydrolytically stable Poor solvent resistance
Good weatherability properties Poor strong acid/strong
Fair oil resistance Base resistance
Good resistance to ozone  
Reasonably good compatibility in blends  

Polyols
Polyethers
 Most common modern back bone of polymers