Polyurea Technology Overview

Presented by:John Durig

1st Annual TRFA MeetingNovember 10, 2003

• History

• Chemistry

• Equipment for spraying

• Surface prep and priming

• Comparison of epoxy, urethane elastomers and polyurea

Polyurea Overview

• Advantages of polyurea systems

• Applications

• Case histories

• Challenges for raw material suppliers

• Summary

Polyurea Overview

• 1981 – developed for automotive RIM parts

• 1987 – polyurea spray technology introduced by Texaco

• 1988 – first commercial usage as an in-field coating

• 1993 – several formulators enter market

Polyurea History

• Amine + Aromatic Isocyanate yields Aromatic Polyurea

• Amine + Aliphatic Isocyanate yields Aliphatic Isocyanate

• No metal catalysts required

Basic Chemistry

Basic Chemistry

Amines Isocyanates

Polyester diamines MDI prepolymers

Polyaspartic esters HDI prepolymers

Aliphatic diamines IPDI

Cyclaliphatic diamines

Amine adducts

Hindered amines

MIX RATIO IS CRITICAL!

Application Equipment

• Plural component

• High pressure (1,500 – 3,000 psi)

• High temperature (140 – 170°F)

• Impingement systems

• 1:1 mix ratio

Equipment Manufacturers

• Gusmer

• Graco

• Glass Craft

• Spray Tech

• AST

Plural Component Equipment

Surface Preparation

• Concrete: follow manufacturer’s recommendations: SHOTBLAST

• Steel: Minimum SP 10/NACE 2 with a 3 mil profile for immersion service

Priming

• Concrete: should be primed and sealed to reduce outgassing

• Carbon Steel: does not require primer

• Stainless Steel, Galvanized Steel, Aluminum and other Substrates:

- See manufacturer

Comparison of Epoxy, Polyurethane Elastomers and Polyurea

Bis A Epoxy PU Elastomer Polyurea

Tensile 7,000 psi 1,000 psi 3,000 psi

Elongation

ASTM D4541

1 % 500 % 425 %

Compressive Strength

ASTM D 695

10,000 psi N/A N/A

Abrasion Resistance

ASTM D 4060

100 mg Loss 42 mg Loss 6.2 mg Loss

Flammability

ASTM E-84

Class A*

Flame spread 0

Smoke Density 0

Class B

Flame Spread > 25

Class A

Flame Spread 10

Smoke Density 35

Comparison of Epoxy, Polyurethane Elastomers and Polyurea, cont.

Bis A Epoxy PU Elastomer Polyurea

Hardness

ASTM D 2240

Shore D 85 Shore D 40-60 Shore D 40-80

Application Temp. 50 - 90F 55 - 90F -20 - 350F

Impact Resistance

ASTM D 2794

F160, R80 LBS > 160 Lbs.

F and R

> 160 Lbs.

F and R

Permeability ASTM E 96 .16 perm-in. .080 perm-in. .02 perm-in.

Dry Time 8 Hours 6 Hours 45 Seconds

Full Cure 7 Days 72 Hours 3 Hours

Advantages of Polyurea

• Fast cure: little down time

• No solvents, VOCs and low odor• Application at -20°F to 350°F

• 1:1 mix ratio preferred

• Excellent physical properties

Advantages of Polyurea, cont.

• High abrasion resistance• Flexible and tough• No low temperature embrittlement

(-40°F)• Excellent adhesion (1,500 – 2,000+ psi

carbon steel)• Repairs quickly at low temp – brush grade• Single high build systems

Limitations & Precautions

• Color stability of aromatic systems

• Evaluate concrete moisture levels

• Surface preparation requirements

• Chemical resistance should always be verified

Polyurea Applications

Parking decks Cooling towers

Mechanical equipment rooms Potable water tanks

Manhole repair Aquariums

Stadiums Fish hatcheries

Rail cars Blast resistant coatings

Wastewater treatment plants Dump truck linings

Polyurea Applications

Warehouse floors Roofing

Pulp and paper plants Freezers

Pipe coatings Ship decking

Submerged pilings Crude oil storage

Airport glycol tanks Mine walls

Joint sealants OEM applications

Gold Bar WWTP Sedimentation TankInstaller: Desco Coatings of Alberta

The Warehouse Club Parking RampInstaller: Spectrum Contracting Corp, Grafton, WI

Motorola Emergency Water Storage TankInstaller: Mobile Enterprises, Fort Worth, TX

Challenges for Raw Material Suppliers

• Polyurea technology will take market share from traditional urethanes and epoxies

• Market needs– Improved chemical resistance

• Solvents• Strong acids• Oxidizing agents

Challenges for Raw Material Suppliers

• Market needs, cont.– Slower systems

• Reduces overspray issues• Improves film appearance• Improves substrate wetting• Reduces film build requirements

– Improve color stability

Summary

Polyurea formulation and application technology have vastly improved over the last 10 years. Growth of this technology will be at the expense of traditional resin systems. This will occur because of the benefit of rapid return to service in combination with performance benefits including low perm rating, outstanding adhesion and toughness.

Summary, cont.

The use of polyurea technology could be dramatically increased if the limitations created by fast cure and limited chemical resistance are overcome by formulators and raw material suppliers.

Successful application requires attention to appropriate surface preparation, priming and maintaining proportioning equipment.