CO<sub>2</sub> derived hydrogen bonding spacer: enhanced toughness, transparency, elongation and non-covalent interactions in epoxy-hydroxyurethane networks

Anitha, S.; Vijayalakshmi, K. P.; Unnikrishnan, G.; Kumar, Krishna

doi:10.1039/c7ta08243f

Cited by 18 publications

(14 citation statements)

References 72 publications

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“…Compared with previously reported self-healing designs based on boroxine adducts, ,, our material is stronger and stiffer (see Table S3 in the Supporting Information). The presence of hydroxyurethanes within the network is expected to provide additional hydrogen bonding interactions and preserve the material for extensive fluidification upon boroxine hydrolytic cleavage. , The role of these cohesive interactions in the PHU was highlighted by dynamic mechanical analysis, comparing NIPU 4 with a network containing no hydroxyurethane functions. H 2 N–PPG–NH 2 (400 g·mol –1 ) was selected to directly react with 2-FBA anhydride for that purpose, keeping the boroxine percentage in weight unchanged in the network (i.e., 39%) .…”

Section: Resultsmentioning

confidence: 99%

Simple Approach for a Self-Healable and Stiff Polymer Network from Iminoboronate-Based Boroxine Chemistry

et al. 2019

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Despite offering robust mechanical properties, polymer networks suffer from a lack of recyclability, reshaping, and healability. Designing stiff and remendable polymer networks that can repair under mild conditions remains a challenge to extend their field of applications. Herein, we describe a simple approach to design a nonisocyanate-based polyurethane network featuring multiresponsiveness (to humidity and temperature) and outstanding healing properties, as obtained by combining iminoboronate and boroxine chemistry. In spite of the presence of abundant dynamic bonds, the network has a high stiffness (Young's modulus of 551 MPa) and tensile strength (11 MPa). CN iminoboronate and B−O boroxine exchange reactions at high temperature enable efficient network recycling over multiple cycles without compromising its properties. Owing to these features, 3D objects could be designed and printed. The present approach provides excellent sustainable and high-performance substitution to conventional polyurethane networks requiring the use of toxic isocyanates.

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Section: Resultsmentioning

confidence: 99%

Simple Approach for a Self-Healable and Stiff Polymer Network from Iminoboronate-Based Boroxine Chemistry

et al. 2019

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“…Remarkably, the epoxy and hydroxyurethane moieties operated in synergy to create high performance adhesives with a maximum lap-shear adhesion value of 27 MPa for a 50/50 TMPTGE/TMPTC molar composition that is ∼1.7 or ∼1.3 higher than pure epoxy or PHU formulations, respectively. The benefit of merging epoxies chemistries with PHU was further confirmed by Anitha et al who introduced hydroxyurethane moieties within amine-cured epoxy systems by utilizing a monofunctional cyclic carbonate additive. At cyclic carbonate content as low as 1–4 mol %, the adhesive performance of epoxy adhesives made of Jeffamine T403 and diglycidyl ether bisphenol A were significantly increased with lap-shear adhesion strength value up to 22 MPa for Al substrate, surpassing the value for the neat epoxy analogue (17 MPa).…”

Section: Approaches For the Preparation Of Nipu-based Adhesives And C...mentioning

confidence: 90%

Poly(hydroxyurethane) Adhesives and Coatings: State-of-the-Art and Future Directions

Gomez-Lopez

Panchireddy

Grignard

et al. 2021

ACS Sustainable Chem. Eng.

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Polyurethane (PU) adhesives and coatings are widely used to fabricate high-quality materials due to their excellent properties and their versatile nature, which stems from the wide range of commercially available polyisocyanate and polyol precursors. This polymer family has traditionally been used in a wide range of adhesive applications including the bonding of footwear soles, bonding of wood (flooring) to concrete (subflooring), in the automotive industry for adhering different car parts, and in rotor blades, in which large surfaces are required to be adhered. Moreover, PUs are also frequently applied as coatings/paints for automotive finishes and can be applied over a wide range of substrates such as wood, metal, plastic, and textiles. One of the major drawbacks of this polymer family lies in the use of toxic isocyanate-based starting materials. In the context of the REACH regulation, which places restrictions on the use of substances containing free isocyanates, it is now urgent to find greener routes to PUs. While non-isocyanate polyurethanes (NIPUs) based on the polyaddition of poly(cyclic carbonate)s to polyamines have emerged in the past decade as greener alternatives to conventional PUs, their industrial implementation is at an early stage of development. In this review article, recent advances in the application of NIPUs in the field of adhesives and coatings are summarized. The article also draws attention to the opportunities and challenges of implementing NIPUs at the industrial scale.

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“…[116] More recently,K umar and co-workers synthesized 4a from BPAGE with NMP as solvent and benzylt riethyl ammonium chloride as catalysta t1 00 8Cu nder 6bar CO 2 . [117] However, the reaction did not go to completion.T he partially carbonated BPAGE monomer could be used for preparing epoxy-hydroxyurethane networks. The synthesis of 4a from BPAGE is often hampered by solidification of the reaction product.…”

Section: Terminal Biscarbonatesmentioning

confidence: 99%

“…[114] 4a-d are oil-based bis-5CCs. [117] However, the reaction did not go to completion.T he partially carbonated BPAGE monomer could be used for preparing epoxy-hydroxyurethane networks. [116] More recently,K umar and co-workers synthesized 4a from BPAGE with NMP as solvent and benzylt riethyl ammonium chloride as catalysta t1 00 8Cu nder 6bar CO 2 .…”

Section: Terminal Biscarbonatesmentioning

confidence: 99%

Polymers Based on Cyclic Carbonates as Trait d'Union Between Polymer Chemistry and Sustainable CO₂ Utilization

et al. 2019

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Given the large amount of anthropogenic CO2 emissions, it is advantageous to use CO2 as feedstock for the fabrication of everyday products, such as fuels and materials. An attractive way to use CO2 in the synthesis of polymers is by the formation of five‐membered cyclic organic carbonate monomers (5CCs). The sustainability of this synthetic approach is increased by using scaffolds prepared from renewable resources. Indeed, recent years have seen the rise of various types of carbonate syntheses and applications. 5CC monomers are often polymerized with diamines to yield polyhydroxyurethanes (PHU). Foams are developed from this type of polymers; moreover, the additional hydroxyl groups in PHU, absent in classical polyurethanes, lead to coatings with excellent adhesive properties. Furthermore, carbonate groups in polymers offer the possibility of post‐functionalization, such as curing reactions under mild conditions. Finally, the polarity of carbonate groups is remarkably high, so polymers with carbonates side‐chains can be used as polymer electrolytes in batteries or as conductive membranes. The target of this Review is to highlight the multiple opportunities offered by polymers prepared from and/or containing 5CCs. Firstly, the preparation of several classes of 5CCs is discussed with special focus on the sustainability of the synthetic routes. Thereafter, specific classes of polymers are discussed for which the use and/or presence of carbonate moieties is crucial to impart the targeted properties (foams, adhesives, polymers for energy applications, and other functional materials).

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CO₂ derived hydrogen bonding spacer: enhanced toughness, transparency, elongation and non-covalent interactions in epoxy-hydroxyurethane networks

Abstract: A CO2-derived cyclic carbonate functional molecule functions as a reactive-cum-H-bonding spacer unit to induce toughness and elongation in a pristine epoxy network.

Cited by 18 publications

References 72 publications

Simple Approach for a Self-Healable and Stiff Polymer Network from Iminoboronate-Based Boroxine Chemistry

Simple Approach for a Self-Healable and Stiff Polymer Network from Iminoboronate-Based Boroxine Chemistry

Poly(hydroxyurethane) Adhesives and Coatings: State-of-the-Art and Future Directions

Polymers Based on Cyclic Carbonates as Trait d'Union Between Polymer Chemistry and Sustainable CO₂ Utilization

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CO2 derived hydrogen bonding spacer: enhanced toughness, transparency, elongation and non-covalent interactions in epoxy-hydroxyurethane networks

Abstract: A CO2-derived cyclic carbonate functional molecule functions as a reactive-cum-H-bonding spacer unit to induce toughness and elongation in a pristine epoxy network.

Cited by 18 publications

References 72 publications

Simple Approach for a Self-Healable and Stiff Polymer Network from Iminoboronate-Based Boroxine Chemistry

Simple Approach for a Self-Healable and Stiff Polymer Network from Iminoboronate-Based Boroxine Chemistry

Poly(hydroxyurethane) Adhesives and Coatings: State-of-the-Art and Future Directions

Polymers Based on Cyclic Carbonates as Trait d'Union Between Polymer Chemistry and Sustainable CO2 Utilization

Contact Info

Product

Resources

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CO₂ derived hydrogen bonding spacer: enhanced toughness, transparency, elongation and non-covalent interactions in epoxy-hydroxyurethane networks

Polymers Based on Cyclic Carbonates as Trait d'Union Between Polymer Chemistry and Sustainable CO₂ Utilization