Synthesis and Characterization of a New Thermoreversible Polyurethane Network

Abstract

A new polyurethane network was synthesized by the Diels–Alder cross-linking reaction of a polyurethane to bisfuryl monomer. Attenuated total reflectance in conjunction with Fourier transform infrared spectroscopy (ATR-FTIR) spectra of the network showed the disappearance of the absorption bands of maleimide and the appearance of new bands attributed to furan-maleimide cycloadduct. Chemical shifts characteristic to the cycloadduct appeared in the proton nuclear magnetic resonance spectra. ATR-FTIR and differential scanning calorimetry (DSC) demonstrated the thermal reversibility of the material by the reproduction of the retro-Diels–Alder and Diels–Alder processes upon heating and cooling. Global kinetic nonisothermal decomposition parameters in nitrogen were determined by the Flynn-Wall-Ozawa method. A three successive stage thermal decomposition mechanism depicted by n order reaction model for each stage was proposed. The validity of the chosen kinetic model and the values of the kinetic parameters of the individual decomposition stages were determined by the multivariate nonlinear regression method.

Precise synthesis of thermoreversible block copolymers containing reactive furfuryl groups via living anionic polymerization: the countercation effect on block copolymerization behavior

“…5(a)). [27][28][29][30] The formation of PBAB2-BM was also proved by comparison of glass transition temperature (T g ) between PBAB2 and PBAB2-BM. As shown in Fig.…”

Thermoresponsive crosslinked isocyanate‐free polyurethanes by Diels‐Alder polymerization

“…In industry, temperature is the easiest stimulus to initiate bond cleavage . There are several temperature reversible bonds but the most used system is the Diels‐Alder reaction (DA) which was already widely studied in PUs …”

Remendable thermosetting polymers for isocyanate-free adhesives: a preliminary study

“…In response to this concern, remendable polymers have been widely studied over the last few decades. 9,12,13 DA reaction is a [4 + 2] cycloaddition between a diene and a dienophile leading to an adduct which dissociates under thermic treatment to turn back into the previous diene and dienophile compounds. 5,6 Polyurethanes (PUs) are very interesting polymer materials allowing a huge variety of industrial applications in paints, coatings, adhesives, sealants and insulation foams.…”

“…As diisocyanates are harmful for human health and the environment, [16][17][18][19][20] the synthesis of non-isocyanate polyurethanes (NIPUs) has recently gained an increasing interest in the chemical industry. [27][28][29] However, if the reversibility of PUs has already been studied, 9,12,13 to the best of our knowledge, the reversibility of PHUs has never been studied. This pathway permits the formation of poly(hydroxyurethane)s (PHU).…”