Dial-a-Durometer (DAD): A Versatile Approach for Polyurethane Elastomer Production Steve Seneker Jordan Duckett Robert Czeiszperger Jessica Lampkowski Timothy O Brien Anderson Development Company
Cast Elastomer Introduction Polyurethane Elastomer Composition Diisocyanate (TDI or MDI) Polyol (Polyester, Polyether PTMEG, PPG) Curative (Aromatic Diamine MBOCA or Short Chain Diol 1,4-BDO) Processing Approaches Prepolymer Quasi-Prepolymer One-Shot MDI versus TDI
Dial-a-Durometer Approach TDI/Ester Prepolymers: 70A, 80A, 83A, 90A, 93A, 95A, 60D, 70D TDI/PTMEG Prepolymers: 83A, 90A, 92A, 95A, 60D, 70D, 75D Dial-a-Durometer Approach: Low-Hardness TDI Prepolymer High-Hardness TDI Prepolymer Blend the two prepolymers to achieve any hardness in between
DAD Advantages/Disadvantages Advantages: Achieve any hardness Reduce prepolymer inventory Eliminate out-of-date prepolymers Reduce exposure to humidity and excessive heat history Cost savings purchasing fewer products at higher volume Disadvantages: Hand Casting: weigh out two prepolymers instead of one Dynamic Applications (high-load wheels ) High Hardness TDI prepolymers: short-chain diols (DEG, DPG, 1,4-BDO) Hard segment with lower melting or softening temperature
Experimental Low-Hardness/High-Hardness TDI Prepolymer Blended at 10 wt% increments Prepolymer temperature: 150 to 212 F MBOCA temperature: 230 to 250 F Curene 107 temperature: Ambient Stoichiometry: 0.95 Mold temperature: 212 F Post-cure conditions: Overnight @ 212 F Ambient conditioning: One month prior to testing
Physical/Mechanical Properties Hardness, Shore D2240 Elongation, % D412 Tensile Strength, psi D412 100% Modulus, psi D412 300% Modulus, psi D412 Die C Tear, pli D624 Split Tear, pli D1938 Compression Set, % D395, Method B (22 hours @ 70 C) Compression Deflection, psi D575 @ 5, 10, 15, 20 and 25% Bashore Rebound D2632
DAD Systems Evaluated TDI/Ester Prepolymers Andur 7 APLM/7 DPLM 70A and 70D Conventional Andur 7-3 APLF/7 DPLM 73A Low-Free and 70D Conventional Andur 7 APLF/6 DPLF 70A and 60D Low-Free TDI/PTMEG Prepolymers Andur 80-5 AP/1-75 DP 83A and 75D Conventional Andur 85 APLF/75 DPLF 85A and 75D Low-Free TDI/PPG Prepolymers Andur 8000 AP/7500 DP 80A and 75D Conventional Andur 8000 APLF/6500 DPLF 80A and 65D Low-Free
TDI/Ester DAD Systems Andur 7 APLM 70 Shore A Conventional TDI/ester prepolymer Liquid at ambient temperature Viscosity: 1900 cps @ 212 F (100 C) Andur 7 DPLM 70 Shore D Conventional TDI/ester prepolymer Liquid at ambient temperature Viscosity: 800 cps @ 212 F (100 C)
Andur 7 APLM/7 DPLM (MBOCA) Andur 7 APLM(wt%) 100 90 80 70 60 50 40 30 20 10 0 Andur 7 DPLM (wt%) 0 10 20 30 40 50 60 70 80 90 100 % NCO (calc.) 2.40 2.91 3.42 3.93 4.44 4.95 5.46 5.97 6.48 6.99 7.50 Stoichiometry (actual) 0.95 0.95 0.95 0.95 0.95 0.95 0.95 0.95 0.95 0.95 0.95 Hardness, Shore 70A (20D) 79A (26D) 88A (32D) 92A (37D) 94A (42D) 96A (47D) 52D 56D 60D 64D 70D ElongaMon, % 670 600 560 540 530 510 480 450 420 380 350 Tensile Strength, psi 5500 6600 7000 7500 8500 8500 8500 8400 8300 8100 7400 100% Modulus, psi 420 630 790 970 1200 1500 1800 2200 2600 3000 3600 300% Modulus, psi 620 1100 1400 1700 2100 2500 3300 3800 4500 5600 5400 Die C Tear, pli 290 370 410 450 480 510 540 590 680 770 960 Split Tear, pli 120 140 150 160 180 200 230 260 300 340 400 Compression Set 22 hrs @ 70 C 22 22 22 22 22 25 26 26 31 39 *** Compress. Deflect. @5% 70 100 140 190 250 310 370 440 510 580 670 @10% 150 230 300 400 510 720 900 1100 1400 1900 2700 @15% 240 380 500 630 800 1000 1400 1700 2100 2900 4200 @20% 300 480 620 780 1000 1300 1700 2100 2600 3500 5000 @25% 380 580 740 920 1200 1500 1900 2400 3100 4000 5700 Bashore Rebound, % 47 42 38 39 41 44 46 47 47 47 47
TDI/Ester DAD System (1) Andur 7 APLM/7 DPLM/MBOCA Hardness 70A to 70D Tensile Strength 5500 psi to 8100 psi (64D) to 7400 psi (70D) Die C Tear Split Tear 290 to 960 pli 120 to 400 pli Compression Set 22 to 40% (65D) Bashore Rebound 47% to 38% (88A) to 47% (70D) Andur 7 APLM/7 DPLM/Curene 107 Hardness 72A to 68D Split Tear 160 to 530 pli Compression Set 26 to 40% (93A)
TDI/Ester DAD System (2) Andur 7-3 APLF/7 DPLM/MBOCA 7-3APLF Viscosity: 1000 cps (1900 cps) @ 212 F (100 C) Hardness 73A (70A) to 70D Tensile Strength 7500 (5500 psi) to 8200 psi (58D) to 7400 psi (70D) Split Tear 200 (120) to 400 pli Compression Set 25 to 40% (53D) (65D) Andur 7-3 APLF/7 DPLM/Curene 107 Tensile Strength 6600 (5200 psi) to 7000 (92A) to 6700 psi (68D) Compression Set 26 to 40% (80A) (93A)
TDI/Ester DAD System (3) Andur 7 APLF/6 DPLF/MBOCA Hardness 70A to 60D (70D, 70D) Tensile Strength 6600 (5500, 7500) to 7800 psi (48D) to 7200 psi (60D) Split Tear 90 (120, 200) to 290 pli Compression Set 25 to 40% (60D) (65D, 53D) Andur 7 APLF/6 DPLF/Curene 107 Hardness 72A to 58D (68D, 68D) Tensile Strength 7200 (5200, 6600) to 7500 (94A) to 7300 psi (58D) Compression Set 26 to 40% (88A) (93A, 80A) Compression Set @58D: 53% (80%, 95%)
TDI/PTMEG DAD System (1) Andur 80-5 AP/1-75 DP/MBOCA Hardness 82A to 75D Tensile Strength 5300 psi to 8300 psi Die C Tear Split Tear 270 to 1100 pli 60 to 240 pli Compression Set 22 to 40% (65D) Bashore Rebound 64% to 48% (93A) to 58% (75D) Andur 80-5 AP/1-75 DP/Curene 107 Hardness 80A to 69D Tensile Strength 6100 psi to 8300 psi (65D) to 7700 psi (69D) Compression Set 30 to 40% (93A)
TDI/PTMEG DAD System (2) Andur 85 APLF/75 DPLF/MBOCA Hardness 85A (82A) to 75D Split Tear @ 85A: 40 pli (70 pli) @ 95A: 80 pli (95 pli) Bashore Rebound 0 to 5 units higher
TDI/PPG DAD System (1) Andur 8000 AP/7500 DP/MBOCA Hardness Tensile Strength 80A to 75D 2100 psi to 6200 psi Die C Tear 220 to 1000 pli Split Tear 55 to 210 pli Compression Set 24 to 40% (57D) Bashore Rebound 20% to 52%
TDI/PPG DAD System (2) Andur 8000 APLF/6500 DPLF/Curene 107 8000 APLF Visc: 5800 cps @ 25 C (77 F) 6500 DPLF Visc: 79,000 cps @ 25 C (77 F) 3600 cps @ 50 C (122 F) Hardness 80A to 65D Tensile Strength 2300 psi to 5100 psi Die C Tear 220 to 700 pli Split Tear 55 to 190 pli Compression Set 64 to 100% Bashore Rebound 58% to 46% (90A) to 57%
DAD Conclusions (1) Broad hardness range with only two prepolymers Physical/mechanical properties comparable to straight prepolymer/curative approach. Useful for both hand cast and meter, mix and dispense operations
DAD Conclusions (2) Limitless Formulation Possibilities: Ester, PTMEG, PPG MBOCA, Curene 107, Lonzacure MCDEA, Versalink 740 M Systematic qualification is recommended for dynamic applications where high load and heat build up is a concern
Questions? Acknowledgments Jordan Duckett Robert Czeiszperger Jessica Lampkowski Timothy O Brien