Advances in Polyurethane and Polyurea Technology Presented by: Jayson L. Helsel, P.E.

KTA-Tator, Inc.

Learning Objectives Comprehension of the Advances in Polyurethane and Polyurea Technology Webinar will enable the participant to:  List various types of polyurethane coatings  Describe the properties of polyurethane coatings  List various types of polyurea coatings  Describe the properties of polyurea coatings  Recognize two SSPC Performance-based Paint Standards for polyurethane and polyurea coatings

Learning Objectives (cont.)  List the basic performance differences between polyurethane and polyurea coatings  Describe the surface preparation requirements for concrete and steel  Describe the coating application equipment typically employed  List the common applications (when and where polyurethane and polyurea coatings are used)

Basic Chemistry/Properties  Polyurethanes  Polyureas  Hybrid coatings

Polyurethanes  Polyurethanes are formed by the reaction between a polyisocyanate and hydroxyl (-OH) containing resin blend

Polyurethanes  Disocyanate can be aromatic or aliphatic  Wide variety of formulations

Polyurethanes  Conventional 2-part (thin film)  Waterborne formulations  Moisture cure polyurethane single component  End product can be polyurethane or polyurea chemistry  100% Solids/Elastomeric

Polyurethanes  Conventional 2-part (thin film)  Slower cure, longer pot life  Waterborne formulations  Use water dispersible polyisocyanates  SSPC Paint Specification No. 36  “Two-Component Weatherable Aliphatic Polyurethane Topcoat, Performance Based”

SSPC Paint No. 36  Weathering levels for color and gloss (accelerated or Florida exposure)  Level 1 (<1000 hrs or <24 months)  Level 2 (<2000 hrs or < 48 months)  Level 3 (>2000 hrs or > 48 months)  Color: max 2.0 ∆E, Gloss: max loss 30

Polyurethanes  Thin-film polyurethanes properties:  Typically aliphatic  Slower cure  Excellent color and gloss retention  Good chemical/solvent resistance  Good hardness/abrasion resistance

Polyurethanes  100% Solids/Elastomeric  Typically aromatic  Fast cure  Hi build, up to 100+ mils

Polyurethanes  100% solids polyurethane properties:  Elongation/flexibility  Excellent chemical/solvent resistance  Moisture sensitive application  Can be applied in low temperatures (below freezing)  Low VOC

Polyureas  Formed by the reaction between an isocyanate component and an amine terminated (-NH 2 ) resin blend

Polyureas  Isocyanate can be aromatic or aliphatic  Aromatic resins will yellow but not crack  Aliphatic resins have excellent weatherability  Wide variety of formulations possible through particular resin blend  Typically 100% solids

Polyureas  100% solids polyurea properties:  Elongation/flexibility  Excellent chemical/solvent resistance  Not sensitive to moisture during application  Can be applied in low temperatures (below freezing)  Thermal shock resistance  Minimize down time  Low VOC

Polyureas  Polyaspartic ester based polyureas are a newer technology  Resin blend based on aliphatic polyaspartic ester  Can have much slower reaction time  Thinner film application  Typical use is analagous to conventional polyurethanes

Polyurethane/Polyurea Hybrids  Hybrid coatings are formed by the reaction between an isocyanate component and a resin blend component  Resin blend may contain amine-terminated and/or hydroxyl-terminated polymers  Wider range for reaction time and performance properties

Polyureas  Fast cure  Moderate cure  Hybrid systems  SSPC Paint Specification No. 39  “Two-Component Aliphatic Polyurea Topcoat Fast or Moderate Drying, Performance Based”

SSPC Paint No. 39  Type 1: Fast Drying (less than 30 minutes)  Type 2: Moderate Drying (30 minutes to 2 hours)  Weathering levels

SSPC Paint No. 39  Weathering Levels  Accelerated weathering levels  1A – 500 hours, max 2.0 ∆E, 20% gloss loss  2A – 1000 hours, max 3.0 ∆E, 30% gloss loss  3A – 2000 hours, max 3.0 ∆E, 40% gloss loss  Outdoor weathering levels  1N – 12 months, max 2.0 ∆E, 35% gloss loss  2N – 24 months, max 3.0 ∆E, 50% gloss loss

SSPC Paint No. 39  Other tests  Solvent Resistance  No visible topcoat removal (100 double rubs)  Pull-Off Adhesion  Average (3 pulls) ≥ 600 psi  Minimum 500 psi

Polyurethane vs Polyurea  Polyureas are faster cure, e.g. seconds  Polyureas not moisture sensitive  Polyurethanes cure slower but are moisture sensitive  May have fewer adhesion problems with polyurethanes

Surface Preparation  Steel  Abrasive blast cleaning to SSPC-SP 10, Near White  Angular surface profile

Surface Preparation  Concrete  Abrasive blast cleaning  Profile/roughening required  Specialized primer may be necessary  Check moisture content

Application Equipment  Thin film polyurethanes and polyureas (polyaspartics)  Conventional or airless spray  100% solids polyurethanes and polyureas  Plural component spray

Application Equipment  Plural component spray equipment  Heats and mixes resin (part A) and curing agent (part B) components automatically in correct proportions  Paint mixture travels directly to spray gun for immediate application  Some coatings may be brush/roller applied

Application Equipment  Plural component spray equipment  Storage to deliver unmixed material  Proportioning Device  Pressure Pump  Mixing Device  Static mixer or air impingement  Delivery system (spray gun)  Flushing system

Application Equipment  Plural component application  Equipment as recommended by coating manufacturer  Requires trained/licensed applicators  Involve coating manufacturer technical representative for projects  Single application (multiple passes)

Application Equipment

Application Equipment

Application Equipment

Polyurethane Applications  Roof coatings  Pipe  Tank interior/exterior  Truck bed liners  Railcars  Parking decks  Anti-graffiti coatings  Caulk/joint/sealant materials

Polyurea Applications  Roof coatings  Pipe  Tank linings  Truck bed liners  Railcars  Parking decks  Caulk/joint/sealant materials

Polyurethane Systems  Conventional polyurethane for steel structures (exterior tank, bridges)  Surface preparation: SP 10, profile 2-3 mils  Application:  Zinc primer @ 3 – 5 mils DFT  Epoxy intermediate @ 4 – 6 mils DFT  Aliphatic polyurethane @ 3 – 5 mils DFT

Polyurethane Systems  Waterborne polyurethane for steel /concrete (anti-graffiti coating)  Surface preparation: abrasive blast cleaning  Application:  Sealer/primer for concrete  2 coats waterborne urethane primer @ 2 – 3 mils DFT/coat  2 coats waterborne urethane finish @ 2 – 3 mils DFT/coat

Polyurethane Systems  Waterborne polyurethane properties  Tensile strength: 5950 psi  Elongation: 150%  Taber abrasion: <45 mg loss/1000 cycles  Graffiti resistance: Level 3, ASTM D6578

Polyurethane Systems  Waterborne polyurethane chemical resistance  MEK double rubs, 300+ cycles  Gasoline: no effect after 7 days  50% NaOH: no effect after 24 hours  10% HCl: no effect after 24 hours  Toluene: no effect after 4 hours

Polyurethane Systems  Steel pipe (exterior) coating  Surface preparation: SP 10, profile 2.5 mils minimum  Application:  100% solids polyurethane @ 13 – 15 mils DFT

Polyurethane Systems  Concrete tank lining  Surface preparation: ASTM D4259/ ICRI 03732, CSP 5  Application:  Epoxy primer @ 5 – 7 mils DFT  100% solids elastomeric polyurethane @ 60 – 80 mils DFT

Polyurethane Systems  Elastomeric polyurethane properties  Shore A hardness: 60  Adhesion to concrete: 350 psi  Elongation: 400%  Tear strength: 150 psi  Tensile strength: 900 psi

Polyurethane Systems  Elastomeric polyurethane chemical immersion  Acetic acid, 10%  Hyrdochloric acid, 10%  Methanol  Nitric acid, 10%  Phosphoric acid, 10%  Sulfuric acid, 30%

Polyurea Systems  Steel tank lining  Surface preparation: SP 10, profile 3 mils  Application: 100% solids aromatic elastomeric polyurea @ 60 – 80 mils DFT

Polyurea Systems  Elastomeric polyurea properties  Shore D hardness: 50  Elongation: 250%  Tensile strength: 2125 psi  Tear strength: 390 psi

Polyurea Systems  Elastomeric polyurea chemical immersion:  Acetic acid, 10%  Ammonium hydroxide, 20%  Hydrochloric acid, 10%  Phosphoric acid, 10%  Sulfuric acid, 10%

Polyurea Systems  Concrete tank lining  Surface preparation: SP 13 / ICRI 03732, CSP 3-5  Application:  Epoxy primer @ 3 – 5 mils DFT  100% solids aromatic polyurea @ 60 – 100 mils DFT

Polyurea Systems  Steel structures (exterior tank, bridges)  Surface preparation: SP 10, profile 2-3 mils  Application:  Zinc primer @ 3 – 4 mils DFT  Aliphatic polyaspartic @ 6 – 9 mils DFT

Polyurea Systems  Polyaspartic properties  Abrasion resistance: 90 mg loss/1000 cycles  Adhesion: 825 psi  Corrosion weathering: 15 cycles ASTM D5894, Rating 10 blistering/corrosion  Freeze/thaw: 30 cycles, no adhesion loss

Polyurea Hybrid Systems  Concrete floor coating  Surface preparation: abrasive blasting/mechanical roughening  Application:  Epoxy primer @ 3 – 5 mils DFT  100% solids elastomeric polyurea hybrid @ 30+ mils DFT

Polyurea Hybrid Systems  Elastomeric polyurea hybrid properties  Shore D hardness: 60  Tensile strength: 2300 psi  Elongation: 100%  Tear resistance: 330 psi  Taber abrasion: 25 mg/1000 cycles

Summary of Key Points  Polyurethanes  Thin film conventional and waterborne  Single component moisture cure  100% solids thick film  Polyureas  100% solids thick film  No moisture sensitivity  Thin film polyaspartics

Summary of Key Points (cont.)  Blast cleaning generally required  Plural component application for 100% solids polyurethane/polyurea  May allow for low temperature applications  Minimize down time

Advances in Polyurethane and Polyurea Technology  Questions?