Add time:07/29/2019         Source:sciencedirect.com

Current polyurethane (PU) industrial and academic research aims at developing non-isocyanate PUs, referred to as NIPUs. Within this context, we report herein the synthesis of original vinylene carbonate (VC) compounds, subsequently used as chain-transfer agents (CTAs) towards the preparation of α,ω-di(VC) telechelic (co)polyolefins from the tandem ring-opening metathesis polymerization (ROMP)/cross-metathesis (CM) of cyclic olefins. Thus, (5-methyl-2-oxo-1,3-dioxol-4-yl)methyl acrylate (VC1), bis((5-methyl-2-oxo-1,3-dioxol-4-yl)methyl) fumarate (VC2), and bis((5-methyl-2-oxo-1,3-dioxol-4-yl)methyl) (E)-hex-3-enedioate (VC3) were synthesized from 4-(hydroxymethyl)-5-methyl-1,3-dioxol-2-one (DMDO-OH). Among these, only VC3 successfully and selectively afforded well-defined α,ω-di(vinylene carbonate) telechelic polyolefins, namely di(VC3)-PCOE and di(VC3)-P(NB-co-CDT), from the ROMP/CM of COE, and norbonene (NB)/trans,trans,cis-1,5,9-cyclododecatriene (CDT), respectively, using Grubbs’ 2nd-generation ruthenium catalyst (G2) under mild operating conditions (CH2Cl2, 40 °C, 3 h). Preliminary investigations on the reactivity of a model VC, namely 4,5-dimethyl-1,3-dioxol-2-one (DMDO), towards nucleophiles such as a primary or secondary amine, promisingly showed the formation of hydroxy-oxazolidone compounds 1 and 2, and oxo-urethane 3 species, respectively. Yet, the ultimate reaction of di(VC3)-PCOE with 2,2′-(ethylenedioxy)bis(ethylamine) (EDR-148) did not give the expected poly(di(hydroxy-oxazolidone)polyolefin) polyaddition type of NIPUs; competing amidation and/or dehydration or urea formation reactions evidenced by detailed NMR, FTIR and MS analyses, were proposed to account for this inefficiency.

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