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

Abstract

This study describes the synthesis and polymerization of a dicyclocarbonate Diels-Alder (DA) adduct to give a thermoresponsive non-isocyanate polyurethane (NIPU). Firstly a model adduct was synthesized by DA reaction between N-methylmaleimide and furfuryl cyclocarbonate ether (FCE). This adduct was characterized by 1 H-NMR and its thermal behavior was studied by 1 H-NMR, and differential scanning calorimetry (DSC). Then a telechelic dicyclocarbonate DA adduct was obtained by DA reaction between a bismaleimide oligomer and FCE in bulk with full conversion. Its thermal behavior was studied by thermogravimetric analysis (TGA) and DSC. The dicyclocarbonate adduct was polymerized by step-growth polymerization with a diamine, Jeffamine EDR148. The polymerization was performed at room temperature (in order to avoid adduct deprotection) with triazabicyclodecene as the catalyst. The obtained polymer was characterized by size exclusion chromatography (SEC) and 1 H-NMR. The polymer thermal behavior was fully characterized by three complementary analyses. By DSC, retro-Diels-Alder temperatures could be measured to be 90-120°C. By a 1 H-NMR kinetic study at 100°C, it could be shown that after 120 min at 100°C, 85% of the adducts are deprotected. Finally, by SEC, it was demonstrated that the obtained NIPU polymer chains undergo thermal scission by rDA reaction.Scheme 2 Furfuryl cyclocarbonate ether (FCE) synthesis.Scheme 3 Model adduct synthesis by DA reaction between FCE and N-methylmaleimide. PaperPolymer ChemistryPolym. Chem. This journal is

Self‐healing semi‐IPN materials from epoxy resin by solvent‐free furan–maleimide Diels–Alder polymerization

“…The thermostability of the DA polyadduct (sample DF 00:100), the epoxy network (sample DF 100:00), and their semi‐IPN (sample DF 50:50) was investigated by TGA and depicted in Figure . All the polymers exhibit a one‐step thermodegradation behavior with the main weight loss appeared at around 300–450 °C, presumably due to ether linkages thermal disconnection as well as the degradation of aromatic rings . The initial decomposition temperature and 10% weight loss temperature occurred between 300 and 380 °C.…”

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

“…Fluorinated compound 2h was prepared from 2-(trifluoromethyl)acrylic acid and glycerol and copolymerizedw ith vinylidene fluoride as ap recursor for the preparation of coatings [80] and of solid copolymer electrolytes. [83] Furfurylg lycidyl ether (FGE),t he precursor of 2k,w as obtained by the reaction of furfuryl alcohol, ap otentially renewable compound available from the hydrogenation of biomass-sourced furfural, [84] and ECH with tetra-n-butylammonium bromide (TBAB) as ap hasetransfer catalyst( PTC) in basic environment (Scheme 5). Compounds 2j and 2k were prepared from ECH.…”

“…They contain cycloalkane rings formed during the syntheticp rocess. [143] In the continuation of their work on thermoresponsive polymers exploiting the reversible Diels-Alderr eaction, [83] Caillol and co-workerst argeted the preparation of cross-linked networks. [155] 4v was obtained by Averous and co-workers from the reaction of the bisacyl halide of aD FA (Radiacid 0970) with two equivalents of GC.…”

“…[83] The Diels-Alder reaction of abismaleimide-terminated polyol (PEPÀPPOÀbm) with 2k was carried out to afford ab iscarbonate prepolymer.T he latter wasf urtherc opolymerized with Jeffamine EDR148 (EDA) in the presenceo ft riazabicyclodecene (TBD) as nucleophilic catalyst. Promising resultsh ave been obtained, in comparison to isocyanate-based PU, owing to the abundance of H-bonding moieties in the PHU chains.…”

“…[147] In principle, this method could also be appliedt ot ransesterifications with GD or GC (Scheme 23 d). [83,105,120,133,134,147,157,167,175,184] For more challenging internal epoxides,e ven harsher reaction conditions, [106,181] the use of supercritical CO 2 ,a nd/orl ong reaction times (up to 4-7 d) have been reported. [210] The use of supported Mo, Ti,T a, or Wc atalysts in the presence of potentially renewable H 2 O 2 as oxidant (Scheme23f)i su nder investigation as ag reener method for the epoxidation of olefinicc ompounds such as fatty acids and vegetableo ils that are precursorsi nt he synthesis of bio-based carbonates.…”