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Secondary Amines for Aliphatic Polyurea Polymers. Mark Posey and Kenneth Hillman Huntsman - Austin Research Labs. Thermoset Resin Formulators Association 2003 Inaugural Conference November 10-11, The Sofitel Philadelphia Hotel, Philadelphia, Pennsylvania. Objectives of This Presentation.
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Secondary Amines for Aliphatic Polyurea Polymers Mark Posey and Kenneth Hillman Huntsman - Austin Research Labs Thermoset Resin Formulators Association 2003 Inaugural Conference November 10-11, The Sofitel Philadelphia Hotel, Philadelphia, Pennsylvania.
Objectives of This Presentation • Introduce JEFFLINK™ 754, Huntsman’s cycloaliphatic chain extender and provide comparisons to CLEARLINK® 1000. • Provide brief overview of aliphatic polyurea. • Provide formulation assistance to get the most out of the molecule. • Demonstrate both sprayed and static-mix coating physical properties and UV resistance. • Demonstrate the conditions at which each product will have superior properties.
Aliphatic Polyurea Overview • Aliphatic coatings do not yellow, however the raw materials are generally more expensive. • There are several aliphatic isocyanates from which to choose, however due to its lower cost and commercial prevalence, IPDI was used in this study.(see next slide) • Prepolymers with PPG-2000 or JEFFAMINE® D-2000 in the 14-16% NCO range are ideal for spray coatings. • In the early 90’s only primary polyetheramines were available which reacted too fast to be practical. • Introduction of secondary cycloaliphatic amines made aliphatic polyurea viable, but more costly option.
Molecular Structures JEFFLINK™ 754 CLEARLINK® 1000
Chain Extender Properties Comparisons JEFFLINK™ 754 CLEARLINK® 1000 Molecular Weight 254 322 Equivalent wt, meq/g 7.87 6.21 Grams/equivalent 127 161 Pvap @ 25ºC, mmHg 0.02 < 0.02 Viscosity @ 25ºC, cP 13 110 @ 16C Density @ 25ºC, g/mL 0.855 0.89
Summary of Chemical Sources Chemical Manufacturer JEFFAMINE® D-2000 HUNTSMAN LLC JEFFAMINE® T-5000 HUNTSMAN LLC TIOXIDE® TiO2 HUNTSMAN TIOXIDE JEFFLINK™ 754 HUNTSMAN LLC CLEARLINK® 1000 UOP (now Dorf Ketal) VESTANAT® IPDI CREANOVA
Summary of ASTM Methods Used • Tensile Strength, psi ASTM D638 - Type IV • Modulus, psi ASTM D638 - Type IV • Percent Elongation, % ASTM D638 - Type IV • Tear Strength, pli ASTM D624 - Die C • Hardness, Shore A/D ASTM D2240-81 • Taber Abrasion - H18 wheel ASTM D4060 1000 grams, 1000 rev. • Gloss ASTM D523
Pneumatic Static Mix Equipment Dual-Cartridge 200 mL Each Side Speed Adjustment
Typical Spray Conditions • Gusmer GX-7 400 Gun, with 212 Pattern Control Disk and 453 Mixing Module. • Feed preheat and hose heat set at 160F. • Due to high isocyanate viscosity, the pressure differential could be up to 500 psig. Typical pressures 2300 psig Iso. / 2000 psig Resin. • Coatings sprayed onto metal/plastic sheets with mold release to obtain free films. Also sprayed directly onto QUV panels.
QUV Testing of Samples • Coating samples were placed in a QUV cabinet with QUVB-313 bulbs for 2012 hours of continuous exposure at 35C Panel Temp. • No UV stabilizers were used and surface cracks formed in all samples within 200 hours exposure. • Surface cracks made gloss measurement difficult. • Retested sprayed samples after 2012 hours QUV exposure for physical properties.
Yellowness Index (YI) Results Hours Sample 0 1458 2012 8276-63-1 4.51 4.23 4.10 (45/55 JL754) 8276-64-1 4.19 2.21 2.19 (45/55 CL1000) 8276-66-1 3.88 2.37 2.42 (50/50 JL754) Aromatic Comparison 0 1 24 8276-72 8.11 23.7 49.4
QUV Testing Conclusions • Due to lack of UV Stabilizer, all samples showed surface cracking by 200 hrs. It is recommended that all IPDI formulations utilize a UV stabilizer. • All samples showed essentially no increase in color, and some slightly decreased their Yellowness Index at 2012 hours. • Samples lost some elongation, but gained strength in the 100% and 300% stress values. • Based upon QUV results, we conclude that JEFFLINK™ 754 and CLEARLINK® 1000 have similar color behavior in aliphatic coating systems.
Conclusions • JEFFLINK™ 754 is faster reacting than CLEARLINK®1000, but not always significantly so. • Neither chain extender can claim to be better at all sets of conditions. Both have good UV stability. • JEFFLINK™ 754 can replace CLEARLINK ®1000, but reformulation and testing is necessary. • Clearlink®1000 produces coatings that are harder and less flexible than JEFFLINK™ 754 at equivalent conditions. • When high NCO requires high chain extender content, 754 can provide a more flexible, cost effective coating.
Wrap-up / More Information • Huntsman is working hard to bring to market new molecules that will further enhance the formulator’s “toolbox”. Please stay tuned to our website and your local salesman for more details. • A paper based upon this data can be obtained from our website. • For more information on our products, please visit: www.huntsman.com, JEFFAMINE.COM, huntsmanpolyurea.com, huntsmanepoxy.com, huntsmanchainextenders.com • A portion of this presentation was delivered at the August 2003 Polyurea Development Association conference in Reno, Nevada.