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International audienceα,ω-Di(glycerol carbonate) telechelic poly(propylene glycol) (PPG), poly(ethylene glycol) (PEG), poly(ester ether) (PEE), and poly(butadiene) (PBD) have been synthesized through chemical modification of the corresponding α,ω-dihydroxy telechelic polymers (PPG-OH2, PEG-OH2, PEE-OH2 and PBD-OH2, respectively). Tosylation of the polymer diols with 4-tosylmethyl-1,3-dioxolan-2-one (GC-OTs) afforded, in high yields, the desired PPG, PEG, PEE and PBD end-capped at both termini with a five-membered ring cyclic glycerol carbonate (4-hydroxymethyl-1,3-dioxolan-2-one, GC). The GC-functionalization of the polymers at both chain-ends has been confirmed by NMR (1H, 13C, 1D and 2D) and FTIR spectroscopies. Using PPG-GC2 to demonstrate the concept, the corresponding polyhydroxyurethanes (PHUs/non-isocyanate polyurethanes (NIPUs)) have been subsequently prepared following a non-isocyanate method upon ring-opening catalyst-free polyaddition of the PPG-GC2 with JEFFAMINEs (Mn = 230-2000 g mol−1). The effect of various additives introduced during the polyaddition reaction has been studied at different temperatures. In particular, addition of LiBr (5 mol%) to the reaction medium was found to slightly promote the cyclocarbonate/amine reaction. The polymerization process was supported by FTIR and SEC analyses

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International audienceTelechelic polycyclooctenes (PCOEs) have been successfully synthesized by ring-opening metathesis polymerization (ROMP)/cross-metathesis (CM) of cyclooctene (COE) using Grubbs' second-generation catalyst (G2) in the presence of epoxide-functionalized chain-transfer agents (CTAs). The monofunctional epoxide oxiran-2-ylmethyl acrylate CTA (1) afforded the isomerized alpha-(glycidyl alkenoate),omega-propenyl functional (IMF) PCOEs. The use of 1,4-benzoquinone (BZQ) as additive completely inhibited the C=C isomerization process, thereby leading selectively to alpha-(glycidyl alkenoate),omega-vinyl telechelic (MF) PCOE. On the other hand, difunctional epoxide CTAs, bis(oxiran-2-ylmethyl) fumarate (3), bis(oxiran-2-ylmethyl) maleate (4), bis(oxiran-2-ylmethyl) (E)-hex-3-enedioate (5), and (Z)-1,4-bis(oxiran-2-ylmethoxy)but-2-ene (6), selectively afforded the corresponding alpha,omega-di(glycidyl alkenoate) telechelic PCOEs (DF) along with minor amounts of cyclic nonfunctional (CNF) PCOE. In the presence of these difunctional symmetric CTAs, the mechanism is proposed to proceed through a tandem one-pot CM/ROMP/ring-closing metathesis (RCM) approach. CM was more effective with Z- than E-configurated CTAs (4 > 6 >> 3 >> 5), regardless of the presence of a methylene group in-between the C=C double bond and the glycidyl moiety. Subsequent dithiocarbonatation of the alpha,omega-diepoxide telechelic PCOEs upon reaction with CS2 in the presence of LiBr quantitatively afforded the first examples of bis(cyclodithiocarbonate) end-functional PCOEs. Ensuing aminolysis of the bis(cyclodithiocarbonate) telechelic PCOEs with the polyether (triethylene glycol) diamine JEFFAMINE EDR-148 quantitatively afforded, at room temperature without any added catalyst, the desired poly(mercaptothiourethane)s NIPUs, as evidenced from FTIR spectroscopy, TGA, and DSC analyses

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