[en] The polyaddition between dicyclic carbonates and diamines leading to poly(hydroxy urethane)s (PHUs) has emerged as the preferred method for the synthesis of green, non-isocyanate polyurethanes. However, when proposed for use as structural adhesives, the long times for completion of aminolysis of the 5-membered cyclic carbonates under ambient conditions force the use of complementary chemistries to accelerate the curing process. In this work, a system that combines an amino-terminated PHU (NH2-PHU-NH2), an epoxy resin, and a thiol compound was employed to develop high-shear strength PHU-epoxy hybrid adhesives able to cure at room temperature in short times. A NH2-PHU-NH2 prepolymer synthesized by using a sub-stoichiometric quantity of dicyclic carbonates was mixed with a bisphenol A-based epoxy resin for the preparation of the structural adhesive. While this adhesive showed good lap-shear strength and shear resistance under static load and temperature, the curing process was slow. In order to speed up the curing process, a thiol (trimethylolpropane tris(3-mercapto propionate)) was added and its impact on the curing process as well as on the adhesive properties was evaluated. The trifunctional thiol additive allowed for faster curing in the presence of the 1,1,3,3-tetramethylguanidine basic catalyst. Moreover, a combination of NH2-PHU-NH2 and the thiol as curing agents for the epoxy resin resulted in adhesives with superior toughness, without any deterioration of the ultimate lap-shear strength or shear resistance under load and temperature, making these adhesives suitable for high-demand applications in the automotive industry.
Research Center/Unit :
CESAM - Complex and Entangled Systems from Atoms to Materials - ULiège Center for Education and Research on Macromolecules (CERM), Belgium
Disciplines :
Materials science & engineering Chemistry
Author, co-author :
Gomez-Lopez, Alvaro; University of the Basque Country, POLYMAT and Department of Polymers and Advanced Materials: Physics, Chemistry and Technology, Donostia/SanSebastian, Spain
Grignard, Bruno ; University of Liège (ULiège), Complex and Entangled Systems from Atoms to Materials (CESAM) Research Unit, Center for Education and Research on Macromolecules (CERM), Belgium
Detrembleur, Christophe ; University of Liège (ULiège), Complex and Entangled Systems from Atoms to Materials (CESAM) Research Unit, Center for Education and Research on Macromolecules (CERM), Belgium
Sardon, Haritz ; University of the Basque Country, POLYMAT and Department of Polymers and Advanced Materials: Physics, Chemistry and Technology, Donostia/SanSebastian, Spain
Language :
English
Title :
Accelerating the Curing of Hybrid Poly(Hydroxy Urethane)-Epoxy Adhesives by the Thiol-Epoxy Chemistry
F.R.S.-FNRS - Fonds de la Recherche Scientifique [BE] EU - European Union [BE]
Funding text :
The authors would like to acknowledge the technical and human support provided by SGIker (UPV/EHU and ERDF, EU). A.G.-L. would like to acknowledge the University of the Basque Country for the predoctoral fellowship received to carry out this work and Dr. Nora Aranburu for the help with the lap-shear measurements. ORIBAY Group Automotive also wants to acknowledge HAZITEK program for the financial support of the project n° ZL-2019/00193. The authors want to acknowledge the financial support of the EU through the project NIPU-EJD 9555700. C.D. is FNRS Research Director and would like to thank FNRS for financial support.
Schulenburg, J. O.; Linnenbrink, M. New Building Blocks for Lightweight Structures. Adhes. Adhes. 2009, 6, 22-27, 10.1007/bf03250462
Schulenburg, J. O.; Kramer, A. Structural Adhesives: Improvements in Vehicle Crash Performance. SAE Trans. 2004, 113, 111-114, 10.4271/2004-01-0244
MarketsandMarkets. Polyurethane Adhesives Market by Resin Type (Thermoset & Thermoplastic), Technology (Solvent-Borne, 100% Solids, Dispersion), End-Use Industry (Automotive, Construction, Packaging, Footwear, Industrial, and Furniture), Region-Global Forecast to 2024, 2020.
Karol, M. H.; Kramarik, J. A. Phenyl Isocyanate Is a Potent Chemical Sensitizer. Toxicol. Lett. 1996, 89, 139-146, 10.1016/s0378-4274(96)03798-8
Bello, B.; Herrick, C. A.; Smith, T. T.; Woskie, S. R.; Streicher, R. P.; Cullen, M. R.; Liu, Y.; Redlich, C. A. Skin Exposure to Isocyanates: Reasons for Concern. Environ. Health Perspect. 2007, 115, 328, 10.1289/ehp.9557
Barbhuiya, M.; Bhunia, S.; Kakkar, M.; Shrivastava, B.; Tiwari, P.; Gupta, S. Fine Needle Aspiration Cytology of Lesions of Liver and Gallbladder: An Analysis of 400 Consecutive Aspirations. J. Cytol. 2014, 31, 20-24, 10.4103/0970-9371.130634
Slocombe, R. J.; Hardy, E. E.; Saunders, J. H.; Jenkins, R. L. Phosgene Derivatives. The Preparation of Isocyanates, Carbamyl Chlorides and Cyanuric Acid1. J. Am. Chem. Soc. 1950, 72, 1888-1891, 10.1021/ja01161a009
Alves, M.; Grignard, B.; Mereau, R.; Jerome, C.; Tassaing, T.; Detrembleur, C. Organocatalyzed Coupling of Carbon Dioxide with Epoxides for the Synthesis of Cyclic Carbonates: Catalyst Design and Mechanistic Studies. Catal. Sci. Technol. 2017, 7, 2651-2684, 10.1039/c7cy00438a
Aomchad, V.; Cristòfol, À.; Monica, F. D.; Limburg, B.; D'Elia, V.; Kleij, A. W. Recent Progress in the Catalytic Transformation of Carbon Dioxide into Biosourced Organic Carbonates. Green Chem. 2021, 23, 1077-1113, 10.1039/d0gc03824e
Guo, L.; Lamb, K. J.; North, M. Recent Developments in Organocatalysed Transformations of Epoxides and Carbon Dioxide into Cyclic Carbonates. Green Chem. 2021, 23, 77-118, 10.1039/d0gc03465g
Gomez-Lopez, A.; Panchireddy, S.; Grignard, B.; Calvo, I.; Jerome, C.; Detrembleur, C.; Sardon, H. Poly(Hydroxyurethane) Adhesives and Coatings: State-of-the-Art and Future Directions. ACS Sustain. Chem. Eng. 2021, 9, 9541-9562, 10.1021/acssuschemeng.1c02558
Ecochard, Y.; Caillol, S. Hybrid Polyhydroxyurethanes: How to Overcome Limitations and Reach Cutting Edge Properties?. Eur. Polym. J. 2020, 137, 109915, 10.1016/j.eurpolymj.2020.109915
Figovsky, O. L.; Shapovalov, L. D., Nonisocyanate Polyurethanes for Adhesives and Coatings. First International IEEE Conference on Polymers and Adhesives in Microelectronics and Photonics. Incorporating POLY, PEP \& Adhesives in Electronics. Proceedings (Cat. No. 01TH8592); IEEE, 2001; pp 257-264.
Figovsky, O. L.; Sklyarsky, L. S.; Sklyarsky, O. N. Polyurethane Adhesives for Electronic Devices. J. Adhes. Sci. Technol. 2000, 14, 915-924, 10.1163/156856100742979
Lambeth, R. H.; Rizvi, A. Mechanical and Adhesive Properties of Hybrid Epoxy-Polyhydroxyurethane Network Polymers. Polymer 2019, 183, 121881, 10.1016/j.polymer.2019.121881
Stroganov, I. V.; Stroganov, V. F. Peculiarities of Structurization and Properties of Nonisocyanate Epoxyurethane Polymers. Polym. Sci., Ser. C 2007, 49, 258-263, 10.1134/s1811238207030113
Anitha, S.; Vijayalakshmi, K. P.; Unnikrishnan, G.; Kumar, K. S. S. CO 2 Derived Hydrogen Bonding Spacer: Enhanced Toughness, Transparency, Elongation and Non-Covalent Interactions in Epoxy-Hydroxyurethane Networks. J. Mater. Chem. A 2017, 5, 24299-24313, 10.1039/c7ta08243f
Rokicki, G.; Wojciechowski, C. Epoxy Resin Modified by Aliphatic Cyclic Carbonates. J. Appl. Polym. Sci. 1990, 41, 647-659, 10.1002/app.1990.070410315
Sudo, A.; Motokucho, S.; Endo, T. A New Series of Cyclic 5-Membered Dithiocarbonates Having Urethane Tether: Application as an Adhesion Promoter to Epoxy-Amine Curing System. J. Polym. Sci., Part A: Polym. Chem. 2008, 46, 2588-2592, 10.1002/pola.22589
Figovsky, O.; Shapovalov, L.; Buslov, F. Ultraviolet and Thermostable Non-Isocyanate Polyurethane Coatings. Surf. Coating. Int. B Coating. Trans. 2005, 88, 67-71, 10.1007/bf02699710
Figovsky, O.; Shapovalov, L.; Axenov, O. Advanced Coatings Based upon Non-Isocyanate Polyurethanes for Industrial Applications. Surf. Coating. Int. B Coating. Trans. 2004, 87, 83-90, 10.1007/bf02699601
Figovsky, O.; Leykin, A.; Shapovalov, L. Non-Isocyanate Polyurethanes-Yesterday, Today and Tomorrow. Altern. Energy Ecol. 2016, 4, 95-108, 10.15518/isjaee.2016.03-04.009
Ma, Z.; Li, C.; Fan, H.; Wan, J.; Luo, Y.; Li, B.-G. Polyhydroxyurethanes (PHUs) Derived from Diphenolic Acid and Carbon Dioxide and Their Application in Solvent-and Water-Borne PHU Coatings. Ind. Eng. Chem. Res. 2017, 56, 14089-14100, 10.1021/acs.iecr.7b04029
Asemani, H.; Zareanshahraki, F.; Mannari, V. Design of Hybrid Nonisocyanate Polyurethane Coatings for Advanced Ambient Temperature Curing Applications. J. Appl. Polym. Sci. 2019, 136, 1-10, 10.1002/app.47266
Lambeth, R. H. Progress in Hybrid Non-Isocyanate Polyurethanes. Polym. Int. 2021, 70, 696-700, 10.1002/pi.6078
Bizet, B.; Grau, E.; Asua, J. M.; Cramail, H. Hybrid Nonisocyanate Polyurethanes (H-NIPUs): A Pathway towards a Broad Range of Novel Materials. Macromol. Chem. Phys. 2022, 223, 2100437, 10.1002/macp.202100437
Ehlers, J.-E.; Rondan, N. G.; Huynh, L. K.; Pham, H.; Marks, M.; Truong, T. N. Theoretical Study on Mechanisms of the Epoxy-Amine Curing Reaction. Macromolecules 2007, 40, 4370-4377, 10.1021/ma070423m
Rozenberg, B. A., Kinetics, Thermodynamics and Mechanism of Reactions of Epoxy Oligomers with Amines BT-Epoxy Resins and Composites II; Dušek, K., Ed.; Springer Berlin Heidelberg: Berlin, Heidelberg, 1986; pp 113-165.
Hoyle, C. E.; Lowe, A. B.; Bowman, C. N. Thiol-Click Chemistry: A Multifaceted Toolbox for Small Molecule and Polymer Synthesis. Chem. Soc. Rev. 2010, 39, 1355-1387, 10.1039/b901979k
Konuray, A. O.; Fernández-Francos, X.; Ramis, X. Analysis of the Reaction Mechanism of the Thiol-Epoxy Addition Initiated by Nucleophilic Tertiary Amines. Polym. Chem. 2017, 8, 5934-5947, 10.1039/c7py01263b
Carioscia, J. A.; Stansbury, J. W.; Bowman, C. N. Evaluation and Control of Thiol-Ene/Thiol-Epoxy Hybrid Networks. Polymer 2007, 48, 1526-1532, 10.1016/j.polymer.2007.01.044
Jin, K.; Heath, W. H.; Torkelson, J. M. Kinetics of Multifunctional Thiol-Epoxy Click Reactions Studied by Differential Scanning Calorimetry: Effects of Catalysis and Functionality. Polymer 2015, 81, 70-78, 10.1016/j.polymer.2015.10.068
Gennen, S.; Alves, M.; Méreau, R.; Tassaing, T.; Gilbert, B.; Detrembleur, C.; Jerome, C.; Grignard, B. Fluorinated Alcohols as Activators for the Solvent-Free Chemical Fixation of Carbon Dioxide into Epoxides. ChemSusChem 2015, 8, 1845-1849, 10.1002/cssc.201500103
Gomez-Lopez, A.; Ayensa, N.; Grignard, B.; Irusta, L.; Calvo, I.; Müller, A. J.; Detrembleur, C.; Sardon, H. Enhanced and Reusable Poly(Hydroxy Urethane)-Based Low Temperature Hot-Melt Adhesives. ACS Polym. Au 2022, 2, 194-207, 10.1021/acspolymersau.1c00053
Gomez-Lopez, A.; Grignard, B.; Calvo, I.; Detrembleur, C.; Sardon, H. Synergetic Effect of Dopamine and Alkoxysilanes in Sustainable Non-Isocyanate Polyurethane Adhesives. Macromol. Rapid Commun. 2020, 42, 2000538, 10.1002/marc.202000538
Gomez-Lopez, A.; Grignard, B.; Calvo, I.; Detrembleur, C.; Sardon, H. Monocomponent Non-Isocyanate Polyurethane Adhesives Based on a Sol-Gel Process. ACS Appl. Polym. Mater. 2020, 2, 1839-1847, 10.1021/acsapm.0c00062
Hill, L. W. Calculation of Crosslink Density in Short Chain Networks. Prog. Org. Coating 1997, 31, 235-243, 10.1016/s0300-9440(97)00081-7
Hill, L. Structure/Property Relationships of Thermoset Coatings. J. Coating Technol. 1992, 64, 28-42
Barral, L.; Cano, J.; López, A. J.; López, J.; Nogueira, P.; Ramírez, C. Isothermal Cure of an Epoxy/Cycloaliphatic Amine System. Vitrification and Gelation. Polym. Int. 1995, 38, 353-356, 10.1002/pi.1995.210380406
Strøbech, C. Polyurethane Adhesives. Int. J. Adhes. Adhes. 1990, 10, 225-228, 10.1016/0950-0618(90)90042-Y
