Polyurea Basic Concepts Rev 0918_1 Primeaux Associates LLC Informal Casual Atmosphere • Welcome to the Polyurea Basic Concepts Course • Follow a PowerPoint Presentation – Course Manual • Ask questions when you have them • Get to know the people in the room – Material suppliers – Equipment suppliers – Contractors – Inspectors – Consultants – Newcomers to the business Introductions • Instructor – Dudley Primeaux II, PCS, CCI – > 50 Technical Publications – Named inventor on > 30 Patents • Class Self Introductions Polyurea Basics, Rev 0918.1 1 Primeaux Associates LLC Polyurea Disclaimer • Not all polyurea’s are created equal • Material covered & physical properties do not apply to all polyurea’s • Many different aspects determine a successful application of polyurea – Material selection for project – Surface preparation – Equipment setup & use – Application techniques What is Polyurea? Polyurea Basics, Rev 0918.1 2 Primeaux Associates LLC What is a “Polyurea”? “Polyurea” is a description of a technology and it in itself is not a coating / lining material. Polyurea Technology • Polyurea is a thermoset material, not a thermoplastic • As with all thermoset materials, there is some “shrinkage” associated with cure • Can be between 0.5 – 5.0% linear! Polyurea Basics, Rev 0918.1 3 Primeaux Associates LLC Polyurea Technology Polyurea Technology Typical Shrinkage, general values Hardness, Shore D Elongation, % Shrinkage, % 60 – 70 < 100 3 – 5 % 50 – 60 ~200 – 250 2 – 4 % 40 – 50 ~250 – 500 1.5 – 2.5 % < 35 ~250 – 800 0.5 – 1.0 % Polyurea Basics, Rev 0918.1 4 Primeaux Associates LLC Polyurea Definition •A pure polyurea coating / elastomer is derived from the reaction product of a polyisocyanate component and an amine-terminated resin blend. For reference purposes, a polyurethane / polyurea hybrid coating / elastomer is the reaction product of a polyisocyanate component and a resin blend component. The resin blend may be made up of blends of amine-terminated and / or hydroxyl-terminated polymer resins. Polyurea Definition From the PDA / SSPC Definition: • Two-part system • One part is Isocyanate component – reactive isocyanate groups ( -NCO) • Other part is a Resin blend component – reactive group is amine (primary or secondary) –( -NH2 or -NH-) • Reaction of the two components yields a urea linkage Polyurea Basics, Rev 0918.1 5 Primeaux Associates LLC Polyurea Reaction Urea linkage Polyurea Technology Polyurea Hybrid’s Polyurethane Polyurea Basics, Rev 0918.1 6 Primeaux Associates LLC Polyurea Technology MDI - aromatic • some TDI based IPDI - aliphatic • also HDI and H12MDI derivatives Polyurea Technology Polyurea Basics, Rev 0918.1 7 Primeaux Associates LLC Polyurea Technology • Primary Amine –fast • Secondary Amines –slower • Aliphatic Amines – Aliphatic systems Also some hindered primary amines Aspartic Technology of “Polyurea” Polyaspartic (Aspartic) Ester Polyurea Systems • Introduced in the early ‘90s – 2° aliphatic diamine + polisocyanate (usually aliphatic) • Slower Cure / Airless Spray – potlife: 2 - 60 min. – tack free dry: 5 - 120 min. • Often Used in Thin Film (<15 mils, < 400µm) Topcoat Applications – non-yellowing/gloss retention – 70 - 100% solids Polyurea Basics, Rev 0918.1 8 Primeaux Associates LLC Aspartic Technology of “Polyurea” • Applications - High Productivity Concepts when “time is money” – Metal Coatings • DTM for Railcar • Powder Coating Replacement for metal poles – Concrete Surface Coatings • Interior Surface of Tunnel (topcoat over conventional polyurea) • San Mateo Bridge Topcoat (over conventional polyurea) • Flooring topcoat (roller applied over epoxy primer) Chemistry Overview • From a chemistry perspective, polyurea is that system were the reaction is with isocyanate and amine terminated resin - no polyols / hydroxyls • Does not always require plural component equipment for application • Can be fast or slow setting • Growing technology Polyurea Basics, Rev 0918.1 9 Primeaux Associates LLC Chemistry Overview Formulation Basics vs Technology Type For the resin blend component (traditional system) Resin Component Chain Extender System Type Polyetheramine / polyamine Amine terminated Polyurea Polyether polyol (-OH terminated) Amine terminated Polyurea/Polyurethane Polyetheramine / polyamine Glycol (-OH terminated) Polyurethane/polyurea Polyether polyol Glycol (-OH terminated) Polyurethane No such thing as a “% Polyurea System” History of the Technology • 1981 - Developed for Automotive RIM • 1986 - Polyurea Spray Systems Developed – Primary objective was for PU Spray Foam Coating • 1987 - Polyurea Spray Technology Introduced to Industry • 1988 - First Commercial Use Polyurea Basics, Rev 0918.1 10 Primeaux Associates LLC Characteristics • Fast, consistent reactivity / no catalysts – Fast return to service • Relative environmental process insensitivity – Extended working season • Excellent mechanical properties – Flexible, seamless, moderate chemicals • Good adhesion to a variety of substrates – With proper surface preparation • 100% solids formulations – No solvents, VOC’s, little to no odor Polyurea Technology Polyurea Basics, Rev 0918.1 11 Primeaux Associates LLC Technology Introduction Texaco Video Systems Available • Aromatic Based Spray Formulations - limited color stability in outdoor applications • Aliphatic Based Spray Formulations - excellent color stability in outdoor applications - more costly than aromatic based systems • NSF/ANSI 61.5 Potable Water Approved • Direct Food Contact approved • Polyaspartic Ester Polyurea (thin film) • Slow Set Joint Sealants • Hand Mix Systems for Repair Polyurea Basics, Rev 0918.1 12 Primeaux Associates LLC Polyurea Elastomer Testing Typical Physical Properties Tensile strength, psi up to 6500 (45 MPa) Shore Hardness A 25 to D 80 Elongation, % up to 1000 Tear strength, pli 250 to 600 (43 – 105 kN/m) 100% Modulus, psi 500 to 2000 (3.5 – 13.8 MPa) Burst strength, psi 250 to 500 (1.7 – 3.5 MPa) Flex/Crack Bridging > 1/8 inch (> 3 mm) -26°C / -15°F Polyurea Basics, Rev 0918.1 13 Primeaux Associates LLC Property Testing: Technical Data Sheets Important Aspects for Applicator Gel Time and Tack Free Time - used to confirm proper processing Shore Hardness - used to affirm that applied on-ratio Property Testing Reactivity and Cure Gel Time: the time, in seconds or minutes, in which the mixed components of a polyurea system change from a liquid / fluid state to a solid. Tack Free: the time, in seconds or minutes, in which there is a absence of tack or stickiness in an applied polyurea system surface. Polyurea Basics, Rev 0918.1 14 Primeaux Associates LLC Property Testing Reactivity and Cure Cure Time: The period of time when a polyurea material attains it’s ultimate physical properties. Caution here as many systems may reach a “cure point” within a short period of time that would allow use in a particular application, but have NOT reached ultimate physical properties. The cure time varies on different formulations, with the high hardness, low elongation systems reaching full cure faster that the slower, higher elongation systems. This ultimate “cure” may be 24 to 48 hours plus after application. Tensile & Elongation For elongation Polyurea Basics, Rev 0918.1 15 Primeaux Associates LLC Tensile Strength ASTM D-638, D-412, EN 12803 • Measure of the relationship of stress to strain. Sometimes referred to as modulus or tensile modulus. Measured in psi (pounds per square inch) or mPa. In lay terms, how much force is required to “move” or “stretch” the elastomer film. Elongation ASTM D-638, D-412, EN 12803 • Measure of the amount of stretch, at break, of the elastomer. Measured in %. Keep in mind, this is related to the Tensile Strength. Polyurea Basics, Rev 0918.1 16 Primeaux Associates LLC Tear Strength ASTM D-624, ISO 34 • Measure of the force per unit thickness it takes to propagate a tear in the standardized elastomer sample. Measured in pli (pounds per linear inch) or N/m (Newton/meters). -(propagation) Hardness ASTM D-2240, ISO 868 • Measure of the resistance of a material to deformation, indentation or scratching (surface). It is a relative term and should not be confused with wear and abrasion resistance. Measures resistance to penetration by a “point”. Use either Shore D or Shore A. Often times confused with stiffness or flexural modulus. Polyurea Basics, Rev 0918.1 17 Primeaux Associates LLC Hardness ASTM D-2240, ISO 868 • Can be used to give an indication as to if coating system has been applied “on-ratio” Hardness ASTM D-2240, ISO 868 Shore A Shore D 100 58 95 46 90 39 85 33 80 29 75 25 70 22 65 19 60 16 55 14 50 12 45 10 Polyurea Basics, Rev 0918.1 18 Primeaux Associates LLC Flexibility & Crack Bridging ASTM C 836 / C 1305 Measure of a coating / lining material’s ability to bridge an existing crack that may move in the substrate. Commonly used for concrete flooring type applications. • Many fast set polyurea elastomer systems note the following result: > 1/8 of an inch (3.2 mm) at -20°C - Need to be cautious of “memory” in the polymer system. Abrasion Resistance ASTM D-4060, DIN 53 754 • Test Method for the Abrasion Resistance of Organic Coatings by the Taber Abraser. • Used as a comparative test method between coating systems. Will give an indication as to how the coating system may perform in a highly abrasive environment. Polyurea Basics, Rev 0918.1 19 Primeaux Associates LLC Abrasion Resistance Abrasion Resistance: ASTM D-4060 Must be sure that you are comparing proper test wheels to the resultant data: CS Wheels: “Rubber Wheels”, Resilient CS-17 (Rubber and