Hybrid Poly(hydroxy urethane)s: Folded-Sheet Morphology and Thermoreversible Adhesion

Abstract

Hybrid poly(hydroxy urethane)s (PHUs) are synthesized by copolymerizing aromatic/alicyclic cyclic carbonates with a polyether amine via addition polymerization. They result into polymers with an average molecular weight of 10 kDa and exhibit solubility in common organic solvents. The hybrid PHUs display T g up to 18 °C. PHUs are enriched with multiple H-bonded interactions and they are assessed using temperature-dependent 1 H NMR and Fourier-transform infrared studies. PHUs possess folded-sheet morphology with nanogap between folds and nanowidth between chains. The secondary interactions bestow thermoreversible property to PHUs, and they display good adhesion to both polar (Al–Al) and nonpolar (HDPE–HDPE) substrates. Hybrid PHUs show improved optical transparency compared to homo PHUs. The PHUs are thermally stable up to 250 °C.

Catalytic Systems for the Synthesis of Biscarbonates and Their Impact on the Sequential Preparation of Non-Isocyanate Polyurethanes

“…The bisphenol A diglycidyl carbonate ( 2b ) is an established precursor for the synthesis of non-isocyanate polyurethanes. ,,− Thus, we choose 2b as a model substrate to study the impact of both catalytic systems on the aminolysis of cyclic biscarbonates 2 with 1,4-diaminobutane ( 4 , Table ). Typically, the synthesis of NIPUs is performed in solution e.g., DMSO or extruders .…”

Innovations in applications and prospects of bioplastics and biopolymers: a review

“…Polyhydroxyurethanes have evolved as one of the few promising sustainable materials to produce urethanes by limiting the use of toxic isocyanates. In some recent studies, the use of CO 2 in synthesizing polyhydroxyurethanes has emerged as an effective way to reduce isocyanate dependency and eliminate 120 million tonnes per year of CO 2 emissions (Nair et al 2019 ). However, polyhydroxyurethane is associated with some limitations related to reaction parameters that can be overcome by using hybrid polyhydroxyurethanes.…”

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

“…Nair et al 43 described the preparation of thermoreversible hot-melt PHU adhesives based on homo- and copolymers of aromatic, bisphenol A-based, and cycloaliphatic, Araldite CY 230-based, bis(cyclic carbonate)s and aminotelechelic oligo(propylene glycol). 43 Beside the good adhesion values up to 9 MPa on aluminum and 2 MPa on high density polyethylene, the authors showed that the substrates could be debonded manually after thermal treatment up to 100 °C for 0.5 h and then rebonded with no noticeable loss of the shear strength values. Additional examples of hot-melt PHU adhesives may be found in the patent literature and mainly differ by the composition and application/curing temperatures of the thermoplastic.…”

“…Hot-melt PHU adhesives are solvent-free systems that are employed by melting thermoplastic polymers on a heated substrate. − Tryznowski et al , fabricated hot-melt PHU adhesives for birch wood. Amino telechelic oligoamides made by the condensation of 1,3-diaminopropane (1,3-DAP) with diethyl tartrate or dimethyl succinate were chain extended with diglycerol dicarbonate providing PHUs containing polyamide segments.…”