One-Pot Synthesis of Natural Rubber-Based Telechelic cis-1,4-Polyisoprenes and Their Use To Prepare Block Copolymers by RAFT Polymerization

Abstract

We investigate the one-pot synthesis of a new α,ω-bistrithiocarbonyl-end functionalized telechelic cis-1,4-polyisoprene (Pip) via metathesis degradation from natural rubber (NR) in the presence of the Grubbs second generation catalyst (GII) and a bistrithiocarbonyl-end functionalized olefin as a chain transfer agent (CTA). When the metathesis degradation of the NR of 2 × 106 g mol−1 molecular weight is performed in toluene at 25 °C using the ratio of [Ip]0/[GII]0/[CTA]0 = 100/1/1 (Ip = isoprene units), a cis-1,4-polyisoprene of 14 000 g mol−1 after 4 h is obtained. The functionality estimated by 1H NMR spectroscopy is equal to 1.5 ± 0.1. The structure of telechelic cis-1,4-polyisoprene was confirmed by combination of 1H NMR, 13C NMR spectroscopy and FTIR. The influence of the CTA concentration was investigated. It was found that using higher concentrations of CTA ([Ip]0/[GII]0/[CTA]0 of 100/1/2 and 100/1/5) lead to form a perfectly telechelic cis-1,4-polyisoprene with a functionality of 2 with no significant difference in values (approximately 6400 g mol−1) and in polydispersity indices (∼1.70). The new well-defined α,ω-bistrithiocarbonyl-end functionalized telechelic cis-1,4-polyisoprenes were used successfully as macromolecular chain transfer agents (macroCTAs) to mediate the RAFT polymerization of t-BA using AIBN as the initiator ([t-BA]0/[macroCTA]0/[AIBN]0 = 500/1/0.4) in toluene at 60 °C leading to well-defined P(t-BA)-b-PIp-b-P(t-BA) triblock copolymers.

Living Radical Polymerization by the RAFT Process – A Third Update

“…A [384] CHMA [384] Q [480] tBA [480] K [481] MMA [481] tBA [481] St [481] St-b-tBA [481] 202 A* [482] tBA [482] tBA-b-AA/tBA [482] CIPEA [340] CIPEA-b-PEGA [340] (Continued ) A [483] NIPAm [483] 204 (Ar 1,3,5-substitution)…”

Simple access to alkoxysilyl telechelic polyolefins from ruthenium-catalyzed cross-metathesis depolymerization of polydienes

“…Similarly, CM depolymerization of polyisoprene or rubbers (natural or synthetic) in organic solvents or ionic liquids 39 using a CTA such as 4-octene, 37 or difunctionalized ones such as cis-1,4-diacetoxy-2-butene, cis-but-2-ene-1,4-diol or a bis(trithiocarbonyl) derivative, successfully gave the corresponding telechelic polymers in very good yields (up to 98%) with a good control of molar masses. 39,40,41,42 Also, scrambling CM reactions between PBD or PIP and olefincontaining polyurethanes resulted in hybrid polyolefin/polyurethane materials with compositions ranging from multiblock to random and displaying enhanced mechanical properties.…”

Olefin metathesis meets rubber chemistry and technology

“…The resulting a,x-bistrithiocarbonyl-end functionalized telechlelic cis-PI was applied in a reversible addition-fragmentation chain transfer (RAFT) polymerization of tert-butyl acrylate (t-BA) to form poly(t-BA)-b-(cis-PI)-b-P(t-BA) triblock co-polymers. Such polymer precursors have great potentials in numerous block copolymer applications such as for materials featuring adhesive properties [112].…”

“…Thus, Fig. 17 Synthesis of a,xbistrithiocarbonyl-cis-1,4-polyisoprene from NR and bistrithiocarbonyl-end functionalized CTA via cross metathesis [112] Fig. 18 Butadiene oligomers obtained during the cross metathesis of SBR with dlimonene (n [ [ m) [113] olefin cross metathesis might have a bright future as a sustainable preparation route toward specific chemicals and polymers in different industrial areas.…”