Synthesis of Poly(ethylene adipate) with a Stable Nitroxyl Radical at Both Chain Ends, and Applications to a Counter Radical for Living Radical Polymerization

Abstract

ABSTRACT:Synthesis ofpoly(ethylene adipate) (PEA) with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) at both chain ends was attained by reaction of 4-hydroxy-TEMPO and PEA with isocyanate groups at the terminals. PEA obtained was found to have the living nitroxyl radical, because the electron spin resonance (ESR) spectrum of the polymer manifested a typical three sharp signals based on TEMPO. TEMPO-supported PEA served as a polymeric counter radical for the radical polymerization of styrene, to quantitatively give the block copolymer of ethylene adipate and styrene. Polymerization proceeded in accordance with a living mechanism, because the molecular weight of the copolymer was proportional to conversion of styrene and reciprocal of initial concentration of TEMPO attached to PEA. Analysis of the copolymer using a thin layer chromatography/flame ionization detection (TLC/FID) clarified that the copolymer contained no homopolystyrene. This absence ofhomopolystyrene implies that no diblock copolymer is formed during polymerization.

Nitroxide‐mediated synthesis of styrenic‐based segmented and tapered block copolymers using poly(lactide)‐functionalized TEMPO macromediators

“…Poly(lactide) functionalized TEMPO (PLA‐TEMPO) macromediators were produced from the ring‐opening polymerization of LA in a similar manner performed earlier for poly(tetrahydrofuran),26 poly(caprolactone),27, 28 and poly(ethylene adipate)29 functionalized TEMPO. Macromediator synthesis was performed in toluene at 80°C using 4‐hydroxy TEMPO (TEMPO‐OH) as the initiator for the ring‐opening polymerization of LA catalyzed by triethyl aluminum (AlEt 3 ).…”

Dixanthate-terminated poly(butylene terephthalate). A novel RAFT/MADIX agent for the synthesis of well-defined triblock copolymers resulting from consecutive step- and chain-growth polymerization processes

“…To this end, a broad range of possibilities can be envisioned with RDRP in the presence of polycondensates as macro-initiators. Most classes of step-growth polymers such as polysulfones, [15][16][17] polyurethanes, 18,19 polyamides, 20,21 poly (ether ether ketone), 22 polycarbonates 23,24 and polyesters [25][26][27][28][29] were already studied in this context.…”

The effect of oligomer blending on the flow properties of polycarbonate

“…The PTBP capped oligomer was added to commercial grade PC of M v =21,000 during washing after polycondensation in the continuous interfacial polymerization process of PC. [12][13][14] The oligomer dispersed PC was separated from the wash and the organic phase was further washed with 0.1 N HCl and distilled water several times. After washing, the organic phase was stored at a constant temperature of 75~78 o and granulated with demetalized water.…”