Supporting Information: Fast healing of polyurethane thermosets using reversible triazolinedione chemistry and shapememory Niels Van Herck and Filip E. Du Prez* Polymer Chemistry Research Group, Centre of Macromolecular Chemistry, Department of rganic and Macromolecular Chemistry, Ghent University, Krijgslaan 21 S4-bis, B-9000 Ghent, Belgium 1
Table of Contents A. SYNTHETIC PRCEDURES F PREVIUSLY REPRTED CMPUNDS... 3 1. Synthesis of 5-(2-phenyl-1H-indol-3-yl)pentan-1-ol (2-Ph-indole-H)... 3 2. Synthesis of 5-(2-phenyl-1H-indol-3-yl)pentyl methanesulfonate (2-Ph-indole-Ms)... 3 3. Synthesis of 4,4 -(4,4 -diphenylmethylene)-bis-(1,2,4-triazoline-3,5-dione) (MDI-TAD)... 3 4. Synthesis of 2,2,5-trimethyl-1,3-dioxane-5-carboxylic acid... 4 5. Synthesis of (2E,4E)-hexa-2,4-dien-1-yl 2,2,5-trimethyl-1,3-dioxane-5-carboxylate (HDE ketal)... 4 6. Synthesis of (2E,4E)-hexa-2,4-dien-1-yl 2,2-bis-(hydroxymethyl)-propanoate (HDE diol)... 4 B. FIGURES AND TABLES... 5 Table S1... 5 Figure S1... 6 Figure S2... Figure S3... Figure S4... Figure S5... 9 Figure S6... 9 Figure S7... 10 Figure S... 10 Figure S9... 11 Figure S10... 11 Figure S11... 12 C. 1 H-NMR SPECTRA...13 Figure S12... 13 Figure S13... 14 Figure S14... 15 Figure S15... 16 Figure S16... 17 Figure S17... 1 Figure S1... 19 Figure S19... 20 Figure S20... 21 D. SEC TRACES...22 Figure S21... 22 E. REFERENCES...23 2
A. Synthetic procedures of previously reported compounds 1. Synthesis of 5-(2-phenyl-1H-indol-3-yl)pentan-1-ol (2-Ph-indole-H) 2-Ph-indole-H was synthesized according to the literature procedure of Roling et al. 1 Yield = 2% (42.5 g). M # = 279.3 g/mol. 1 H-NMR (400 MHz, CDCl3): δ (ppm) =.00 (br. s, 1H), 7.63 (d, 1H), 7.55 (d, 2H), 7.4 (t, 2H), 7.3 (m, 2H), 7.21 (td, 1H), 7.14 (td, 1H), 3.61 (t, 2H), 2.91 (t, 2H), 1.76 (m, 2H), 1.5 (m, 2H), 1.45 (m, 2H), 1.16 (br. s, 1H). 2. Synthesis of 5-(2-phenyl-1H-indol-3-yl)pentyl methanesulfonate (2-Ph-indole-Ms) 2-Ph-indole-Ms was synthesized according to the literature procedure of Roling et al. 1 Yield = 99% (47.59 g). M # = 357.47 g/mol. 1 H-NMR (400 MHz, CDCl3): δ (ppm) =.06 (br. s, 1H), 7.62 (d, 1H), 7.55 (d, 2H), 7.4 (t, 2H), 7.3 (m, 2H), 7.21 (td, 1H), 7.14 (td, 1H), 4.16 (t, 2H), 2.93 (s, 3H), 2.93 (t, 2H), 1.74 (m, 4H), 1.46 (m, 2H). 3. Synthesis of 4,4 -(4,4 -diphenylmethylene)-bis-(1,2,4-triazoline-3,5-dione) (MDI-TAD) MDI-TAD was synthesized according to the literature procedure of Billiet et al. 2 Yield = 9% (9.1 g). M # = 362.31 g/mol. 1 H-NMR (300 MHz, DMS-d6): δ (ppm) = 7.47 (d, 4H), 7.37 (d, 4H), 4.10 (s, 2H). 3
4. Synthesis of 2,2,5-trimethyl-1,3-dioxane-5-carboxylic acid 2,2,5-Trimethyl-1,3-dioxane-5-carboxylic acid was synthesized according to the literature procedure of Yim et al. 3 Yield = 69.5% (90.20 g). M # = 174.19 g/mol. LC-MS (m/z) = 175.2 [M+H + ]. 1 H-NMR (400 MHz, CDCl3): δ (ppm) = 10.74 (s, 1H), 3.93 (dd, 4H), 1.44 (s, 3H), 1.41 (s, 3H), 1.21 (s, 3H). 13 C-NMR (100 MHz, CDCl3): δ (ppm) = 10.24 (C()H), 9.34 (C), 65.7 (CH2), 41.76 (C), 25.23 (CH3 (ax.)), 21.96 (CH3 (eq.)), 1.44 (CH3). 5. Synthesis of (2E,4E)-hexa-2,4-dien-1-yl 2,2,5-trimethyl-1,3-dioxane-5-carboxylate (HDE ketal) HDE ketal was synthesized according to the literature procedure of Houck et al. 4 Yield = 72% (26.4 g). M # = 254.33 g/mol. HR-ESI-MS (m/z) = calc.: 277.14103, found: 277.14132 [M+Na + ]. 1 H-NMR (400 MHz, CDCl3): δ (ppm) = 6.20 (m, 1H), 5.97 (m, 1H), 5.69 (m, 1H), 5.57 (m, 1H), 4.57 (d, 2H), 3.6 (dd, 4H), 1.70 (d, 3H), 1.36 (s, 3H), 1.32 (s, 3H), 1.14 (s, 3H). 13 C-NMR (100 MHz, CDCl3): δ (ppm) = 174.01 (C), 134.5 (CH), 131.32 (CH), 130.43 (CH), 123.49 (CH), 9.07 (C), 66.00 (2 x CH2), 65.30 (CH2), 41.1 (C), 24.12 (CH3 (eq.)), 23.21 (CH3 (ax.)), 1.74 (CH3), 1.14 (CH3). 6. Synthesis of (2E,4E)-hexa-2,4-dien-1-yl 2,2-bis-(hydroxymethyl)-propanoate (HDE diol) HDE diol was synthesized according to the literature procedure of Houck et al. 4 Yield = 99% (20.5 g). M # = 214.26 g/mol. HR-ESI-MS (m/z) = calc.: 237.10973, found: 237.10952 [M+Na+]. 1H-NMR (400 MHz, CDCl3): δ (ppm) = 6.20 (m, 1H), 5.97 (m, 1H), 5.69 (m, 1H), 5.57 (m, 1H), 4.59 (d, 2H), 3.75 (dd, 4H), 2.74 (t, 2H), 1.70 (d, 3H), 1.00 (s, 3H). 13C-NMR (100 MHz, CDCl3): δ (ppm) = 175.5 (C), 135.36 (CH), 131.77 (CH), 130.45 (CH), 123.26 (CH), 6.33 (CH2), 65.6 (CH2), 49.32 (C), 1.26 (CH3), 17.27 (CH3). 4
B. Figures and Tables Table S1: 3-level design outline for 5 factors. Experiment PCL Mw wt% HS mol% # mol% free indole Curing temp. PU-1 0 + + - - PU-2 0 - - + + PU-3 + 0 - - + PU-4-0 + + - PU-5 + - 0 + - PU-6 - + 0 - + PU-7 + - + 0 + PU- - + - 0 - PU-9 + + + + 0 PU-10 - - - - 0 PU-11 0 0 0 0 0 5
Cut Puncture Before healing After healing Before healing After healing PU-65-50 PU-65-35 PU-65-20 PU-50-50 PU-50-35 PU-50-20 Figure S1: ptical microscope images before and after healing of the samples (30 min at 120 C) from cut and puncture damage. 6
Cross cut Puncture Before healing After healing Before healing After healing PU-65-20 PU-50-50 PU-65-35 PU-50-35 PU-50-20 No clear image could be obtained 7
PU-65-50 Figure S2: Scanning electron microscope images before and after healing of the samples (30 min at 120 C) from cut and puncture damage. Figure S3: General scheme for the synthesis of an irreversible TAD-HDE tetrafunctional crosslinker. Figure S4: Thermogravimetric analysis for all PU samples.
Figure S5: Differential scanning calorimetry for sample PU-50-35. Similar thermograms were obtained for all samples. Figure S6: Stress-strain measurements of the original PU networks. 9
Figure S7: Arrhenius plot of relaxation times obtained for PU-50-50. Linear fitting allows determination of the activation energy for reversible exchange. Figure S: Temperature sweep of PU-50-20 to show absence of crossover (G = G ) when heating the material to 140 C. 10
Figure S9: Frequency sweep of irreversible analogue of PU-50-20 at 120 C. Figure S10: Stress-strain measurements of PU networks after each recycling step. 11
Figure S11: Infrared spectrum before and after recycling of PU-50-20. The spectrum of the recycled sample was displayed with an offset of 10% for clarity. 12
C. 1 H-NMR spectra 0.9 0.99 1.93 1.95 2.00 1.01 1.00 1.95 1.95 1.9 2.9 2.05 1.01.00 7.64 7.62 7.56 7.55 7.4 7.39 7.37 7.26 CDCl3 7.21 7.14 3.61 2.91 1.76 1.5 1.45 1.16 1 19 20 H 21 16 17 7 9 6 4 5 3 NH 1 2 15 14 10 13 11 12 EtAc 11,15 12,14 9 6,13 7 1 21 EtAc 20 16 19 1 17 EtAc.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 Chemical Shift (ppm) 3.0 2.5 2.0 1.5 1.0 0.5 0.0 Figure S12: 1 H-NMR spectrum (400 MHz, CDCl3) of 5-(2-phenyl-1H-indol-3-yl)pentan-1-ol (2- Ph-indole-H). 13
.06 7.63 7.61 7.56 7.54 7.4 7.3 7.26 CDCl3 7.21 7.14 4.16 16,25 2.93 1.75 1.73 1.46 1 19 23 24 S 22 20 21 CH 3 25 16 17 7 9 6 4 5 3 NH 1 2 15 14 10 13 11 12 20 12,14 11,15 1 9 6,13 7 17,19 1 0.9 1.00 1.99 1.99 1.99 1.02 1.00 1.94 4.9 3.95 2.03 THF THF.5.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 Chemical Shift (ppm) 3.0 2.5 2.0 1.5 1.0 0.5 0.0 Figure S13: 1 H-NMR spectrum (400 MHz, CDCl3) of 5-(2-phenyl-1H-indol-3-yl)pentyl methanesulfonate (2-Ph-indole-Ms). 14
0.95 0.99 1.97 1.97 1.95 1.00 1.00 4.22 1.96 1.99 1.95 1.90 3.52 1.9 2.03 2.02 3.74 2.90.05 7.63 7.61 7.56 7.54 7.47 7.39 7.36 7.26 CDCl3 7.20 7.14 4.15 4.13 4.11 4.10 3. 3.6 3.5 3.3 3.70 3.6 3.67 3.65 2.93 2.91 2.9 2.75 2.73 2.72 2.05 1.76 1.66 1.43 1.01 16 17 1 19 25 H 329 C 23 24 22 27 20 21 H 26 H 2 EtAc EtAc 29 7 9 6 4 5 3 NH 1 2 10 15 14 11 12 13 EtAc 20 1 11,15 12,14 6,13 7 9 25',27' 25'',27'' 16 26,2 17 19 1.5.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 Chemical Shift (ppm) 3.0 2.5 2.0 1.5 1.0 0.5 0.0 Figure S14: 1 H-NMR spectrum (400 MHz, CDCl3) of 5-(2-phenyl-1H-indol-3-yl)pentyl 2,2-bis- (hydroxymethyl)-propanoate (2-Ph-indole diol). 15
4.02 4.23 2.00 7.49 7.46 7.3 7.36 4.10 2.50 DMS-d6 13 2 N 3 N 4 9 10 14 15 25 26 7 11 16 1 N 12 17 N 1 19 5 20 6 27 24 23 N 21 N 22,12,17,26 9,11,16,25 14 H2 11.0 10.5 10.0 9.5 9.0.5.0 7.5 7.0 6.5 6.0 5.5 5.0 Chemical Shift (ppm) 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 Figure S15: 1 H-NMR spectrum (400 MHz, DMS-d6) of 4,4 -(4,4 -diphenylmethylene)-bis- (1,2,4-triazoline-3,5-dione) (MDI-TAD). 16
1.07 2.01 2.04 6.11 3.00 10.74 7.26 CDCl3 4.20 4.17 3.69 3.66 1.44 1.41 1.21 H 12 10 9 11 5 CH 3 4 6 1 3 2 CH 3 CH 3 7 11 7, 6',4' 6'',4'' 12 11.5 11.0 10.5 10.0 9.5 9.0.5.0 7.5 7.0 6.5 6.0 5.5 5.0 Chemical Shift (ppm) 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 Figure S16: 1 H-NMR spectrum (400 MHz, CDCl3) of 2,2,5-trimethyl-1,3-dioxane-5-carboxylic acid. 17
1.00 1.00 1.00 0.99 2.02 2.04 2.04 3.03 6.12 3.07 7.26 CDCl3 6.29 6.26 6.25 6.22 6.0 6.04 6.02 5.79 5.7 5.76 5.74 5.72 5.70 5.65 5.63 5.62 5.60 5.5 4.64 4.63 4.20 4.17 3.65 3.62 1.77 1.75 1.42 1.39 1.21 17 H 31 C 16 15 14 13 12 10 9 11 5 CH 3 4 6 1 3 2 CH 3 7 CH 3 11 7, 6',4' 6'',4'' 13 1 15 16 17 14 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 Chemical Shift (ppm) 3.0 2.5 2.0 1.5 1.0 0.5 Figure S17: 1 H-NMR spectrum (400 MHz, CDCl3) of (2E,4E)-hexa-2,4-dien-1-yl 2,2,5- trimethyl-1,3-dioxane-5-carboxylate (HDE ketal). 1
7.26 CDCl3 6.30 6.2 6.26 6.24 6.09 6.05 6.02 5.1 5.79 5.7 5.76 5.74 5.72 5.66 5.64 5.62 5.60 5.5 4.67 4.66 3.93 3.91 3.90 3. 3.74 3.72 3.71 3.69 2.3 2.1 2.79 1.7 1.76 15 1.06 H 3 C 9 7 6 5 4 1 3 CH 3 2 15 13 10 11 H 12 H 14 4 11'',13'' 11',13' 12,14 9 6 7 5 1.00 1.01 1.01 0.99 1.94 2.01 2.02 1.90 2.99 2.96.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 Chemical Shift (ppm) 3.0 2.5 2.0 1.5 1.0 0.5 0.0 Figure S1: 1 H-NMR spectrum (400 MHz, CDCl3) of (2E,4E)-hexa-2,4-dien-1-yl 2,2-bis- (hydroxymethyl)-propanoate (HDE diol). 19
36.53 2.00 36.3 74.97 36.51 7.26 CDCl3 4.04 4.03 4.01 3.62 3.61 3.59 2.29 2.27 2.25 1.62 1.35 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 Chemical Shift (ppm) 3.0 2.5 2.0 1.5 1.0 0.5 0.0 Figure S19: 1 H-NMR spectrum (400 MHz, CDCl3) of poly(ε-caprolactone) diol 4000 (PCL4000). 20
52.35 2.00 52.30 105.92 52.51 MeH 7.26 CDCl3 4.05 4.03 4.01 3.63 3.61 3.60 2.30 2.2 2.26 1.62 1.35 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 Chemical Shift (ppm) 3.0 2.5 2.0 1.5 1.0 0.5 0.0 Figure S20: 1 H-NMR spectrum (400 MHz, CDCl3) of poly(ε-caprolactone) diol 6000 (PCL6000). 21
D. SEC traces Figure S21: Molecular weight distribution of SEC traces of PCL4000 (blue curve) and PCL6000 (red curve) in THF. Molecular weights were determined using polystyrene standards, explaining the difference in expected and obtained results. 22
E. References (1) Roling,.; De Bruycker, K.; Vonhören, B.; Stricker, L.; Körsgen, M.; Arlinghaus, H. F.; Ravoo, B. J.; Du Prez, F. E. Rewritable Polymer Brush Micropatterns Grafted by Triazolinedione Click Chemistry. Angew. Chem. Int. Ed. 2015, 54, 13126-13129. (2) Billiet, S.; De Bruycker, K.; Driessen, F.; Goossens, H.; Van Speybroeck, V.; Winne, J. M.; Du Prez, F. E. Triazolinediones enable ultrafast and reversible click chemistry for the design of dynamic polymer systems. Nat. Chem. 2014, 6, 15 21. (3) Yim, S. H.; Huh, J.; Ahn, C. H.; Park, T. G. Development of a Novel Synthetic Method for Aliphatic Ester Dendrimers. Macromolecules 2007, 40 (2), 205 210. (4) Houck, H. A.; De Bruycker, K.; Barner-Kowollik, C.; Winne, J. M.; Du Prez, F. E. Tunable Blocking Agents for Temperature-Controlled Triazolinedione-Based Cross-Linking Reactions. Macromolecules 201, DI: 10.1021/acs.macromol.7b02526. 23