Carbamate thermal decarboxylation for the design of non-isocyanate polyurethane foams

Abstract

Polyurethane foams remain at the forefront of cushioning, insulation, packaging, and structural applications. Risk of exposure to isocyanate-containing precursors during foaming operations directly contributes to the regulation of isocyanates, thus...

Waterborne Polyurethane Latexes for Vat Photopolymerization

“…9−11 In contrast, rigid PUs employ higher concentrations of hydrogen-bond-containing hard segments, which lead to higher T g s and moduli. 12,13 This feature of modular design empowers PUs to impact a wide range of technologies, including coatings, 14,15 adhesives, 16,17 biomedical materials, 18−20 automotive parts, 21−23 foams, 24,25 electronics, 26 and more. 27 Traditionally, the processing of thermoplastic polyurethanes (TPUs) employs injection molding, extrusion, blow molding, and compression molding.…”

“…Polyurethanes (PUs) offer superior versatility compared to conventional VP resins due to modular molecular design strategies that effectively tailor thermomechanical properties for specific applications. PUs represent a subgroup of elastomeric materials that rely on soft segments with a low glass transition temperature ( T g ) to provide flexibility and hard segments with intermolecular hydrogen bonding that impart physical cross-linking and provide desirable mechanical performance. − In contrast, rigid PUs employ higher concentrations of hydrogen-bond-containing hard segments, which lead to higher T g s and moduli. , This feature of modular design empowers PUs to impact a wide range of technologies, including coatings, , adhesives, , biomedical materials, − automotive parts, − foams, , electronics, and more …”

Nonisocyanate Polyurethane Segmented Copolymers from Bis‐Carbonylimidazolides

“…This synthesis readily produces both linear and crosslinked architectures and exhibits in situ CO 2 formation for producing NIPU foams. [31,32] The phase separation behavior of BCI-derived NIPU segmented copolymers has not been thoroughly investigated or reported. This manuscript demonstrates phase separation within polyether urethanes synthesized in the absence of isocyanates.…”

CO2-Blown Nonisocyanate Polyurethane Foams

“…Monie et al reported a self-blown NIPU foams based on decarboxylation of cyclic carbonates by thiols or latent thiol via S-alkylation at 80–100 °C. , Bourguignon et al reported self-blown NIPU foams by water-induced decarboxylation of cyclic carbonate at 80–100 °C . Recently, Sintas et al reported a CO 2 -blown NIPU foam through thermal decarboxylation of bis-carbonylimidazolide monomers at 160 °C . The current foaming processes for NIPU require flammable and noxious chemicals, nonsustainable blowing agents, or high temperatures.…”

“…Physical blowing agents such as Solkane 14−17 (hydrofluorocarbon) and supercritical CO 2 , 18 chemical blowing agents such as CO 2 generated from maleic acid/citric acid 19,20 and NaHCO 3 21 were also studied for preparing NIPU foams. Self-blown NIPU foams were reported based on the in situ carbon dioxide generation from partial decarboxylation of sorbitol-derived bis(cyclic carbonate)s 22 or resorcinol-based bis(cyclic carbonate)s 23 27 The current foaming processes for NIPU require flammable and noxious chemicals, nonsustainable blowing agents, or high temperatures. Therefore, the development of a sustainable foaming method for NIPU at lower temperatures is of great interest.…”