Solvent‐free and nonisocyanate melt transurethane reaction for aliphatic polyurethanes and mechanistic aspects

Deepa, P.; Jayakannan, M.

doi:10.1002/pola.22578

Cited by 96 publications

(82 citation statements)

References 36 publications

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“…For PUs synthesized without isocyanates, various pathways are involved, including the reaction between cyclic carbonates and polyfunctional amines [3,4], self-condensation of AB-type monomers containing hydroxyl and acyl azide groups [5], transurethane reactions between diurethanes and diols [6], and reactions between AB-type monomers containing hydroxyl and methyl carbamate groups [5]. In this book, we focus on the production of PUs through reactions of polyols with isocyanates.…”

Section: Introductionmentioning

confidence: 99%

Introduction to Bio-based Polyols and Polyurethanes

Luo

2015

SpringerBriefs in Molecular Science

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Polyurethanes (PUs) are one of the most versatile polymers and are widely used in our daily lives for rigid and flexible foams, coatings, films, and other products. PUs are generally synthesized through reactions between isocyanates and polyols. A brief overview of the chemical structures, origin, synthetic methods, and properties of polyols and isocyanates is given in this chapter. Currently, most polyols are petroleum-based, but increasing concerns over the depletion of petroleum resources, environment, and sustainability have led to considerable efforts to develop bio-based polyols and PUs from renewable resources. Bio-based polyols and isocyanates for the production of bio-based PUs are discussed in this chapter.

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Section: Introductionmentioning

confidence: 99%

Introduction to Bio-based Polyols and Polyurethanes

Luo

2015

SpringerBriefs in Molecular Science

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“…In the prior NIR melt-polymerization study of Deepa [9], dimethyl carbonate (DMC) and aliphatic diamines were used as the starting materials to synthesize polyurethanes under non-solvent conditions (indicated in Fig. 1).…”

Section: Introductionmentioning

confidence: 99%

Solvent-free processes to polyurea elastomers from diamines and diphenyl carbonate

Pan

Liao²,

Lin

et al. 2015

J Polym Res

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Two solvent-free processes without using volatile organic chemical (VOC) for making polyurea elastomers have been successfully developed from diamines and diphenyl carbonate (DPC) to meet stringent public demands for a high standard green alternative Anastas and Eghbali (Chem Soc Rev 39 (1): [301][302][303][304][305][306][307][308][309][310][311][312] 2010). In this new non-isocyanate route (NIR) which is an improvement over our previous process to polyurea elastomers, molten DPC are utilized as the carbonylation agents, where DPC reacts sequentially with 1,6-hexanediamine (HDA), polyether diamines of 2000 molecular weight and short chain diamines such as isophorondiamine (IPDA) or 4,4′-diaminodicyclohexylmethane (H 12 MDA). No solvent was added in the synthesis of these new non-solvent polyurea. Alternatively, the above process was modified with an 3 % addition of a water dispersant such as 3-[(2-aminoethyl)amino]-1-propane sulfonic acid sodium salt (ESA) to make waterborne polyurea elastomers to facilitate the mixing in the preparation and in the film-making steps for the final products. In both solvent-free processes, the longchained polyether diamine and the phenol generated from the displacement reaction of diphenyl carbonate were utilized as diluents to lower the viscosities of the reaction mixtures. Unexpectedly, ultra high molecular weight products were resulted particularly for the waterborne polyurea products measuring in excess of 1,000,000 g/mol in some cases. All samples were characterized by FT-IR, H-NMR, TGA, DSC, AFM and GPC. Since the polymers were prepared under mild conditions in absence of a VOC solvent, the new products were found to mostly exist in highly phase-segregated states, exhibiting high heat-resistant temperatures with T d(5%) of well over 300°C with high elongation (>600 %) for the optimized products. Thus, this solvent-free syntheses and environmentfriendly polyurea products should find usefulness in many practical applications.

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“…For that reason, a non‐isocyanate (the so‐called NIPU: non‐isocyanate polyurethane) synthetic method needs to be developed for replacing isocyanates in order to accomplish green chemistry and as a response to concerns about health and safety in the production of PU from renewable resources. Recently, the most investigated isocyanate‐free methods are via transurethane polycondensation of various amines and alcohols, AB‐type self condensation and aminolysis of cyclic carbonate . However, among these routes, the most attractive one is the step‐growth polyaddition of diamines with dicyclocarbonates that leads to production of NIPUs.…”

Section: Introductionmentioning

confidence: 99%

In situ development of bio‐based polyurethane‐blend‐epoxy hybrid materials and their nanocomposites with modified graphene oxide via non‐isocyanate route

Doley

Sarmah

Sarkar

et al. 2018

Polymer International

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We developed a series of sunflower oil‐based non‐isocyanate polyurethane (NIPU)‐blend‐epoxy hybrid materials (HNIPUs) and their nanocomposites with amine‐functionalized graphene oxide (AF‐GO). Firstly, carbonated sunflower oil (CSFO) containing five‐membered cyclocarbonate groups was synthesized by the reaction of epoxidized sunflower oil with carbon dioxide (CO2) at a pressure of 50 bar and temperature of 110 °C. Then, a series of HNIPUs were synthesized using a mixture of CSFO and a commercially available epoxy resin in various amounts (10, 20 and 30 wt% with respect to CSFO) using isophorone diamine as the curing agent. The HNIPU with 30 wt% epoxy showed the best mechanical properties. Finally, nanocomposites of 30 wt% HNIPU‐based composition were prepared with various amounts of AF‐GO (0.3, 0.6 and 1.0 wt%) and were characterized using Fourier transform infrared and 1H NMR spectroscopies, X‐ray diffraction and scanning electron microscopy. These results emphasize the potentiality of this environmentally friendly approach for preparing renewable HNIPU and nanocomposite materials of high performances. © 2018 Society of Chemical Industry

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Solvent‐free and nonisocyanate melt transurethane reaction for aliphatic polyurethanes and mechanistic aspects

Cited by 96 publications

References 36 publications

Introduction to Bio-based Polyols and Polyurethanes

Introduction to Bio-based Polyols and Polyurethanes

Solvent-free processes to polyurea elastomers from diamines and diphenyl carbonate

In situ development of bio‐based polyurethane‐blend‐epoxy hybrid materials and their nanocomposites with modified graphene oxide via non‐isocyanate route

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