Preparation of macrodiols and polyols by chopping high-molecular-weight aliphatic polycarbonates

• Published in: Journal of polymer science. Part A, Polymer chemistry Polymer chemistry, 2014-06, Vol.52 (11), p.1570-1580
• Main Authors: Jeon, Jong Yeob, Hwang, Eun Yeong, Eo, Seong Chan, Lee, Bun Yeoul
• Format: Article
• Language: English
• Subjects: Alkoxides; Applied sciences; biodegradable; Butanediol; Carbonates; Catalysts; Chain branching; Condensation polymerization; Cutting; Diols; Ethane; Exact sciences and technology; Manganese; NMR; Nuclear magnetic resonance; Oligomers; Organic polymers; Physicochemistry of polymers; Polycondensation; Polymers; Polyols; Polyurethane resins; polyurethanes; Preparation, kinetics, thermodynamics, mechanism and catalysts; Room temperature; Sodium; Triols; Weight
• ISSN: 0887-624X; 1099-0518
• DOI: 10.1002/pola.27150

ABSTRACT High‐molecular‐weight poly(1,4‐butylene carbonate) (PBC) (Mn: 40,000−90,000) was prepared through the condensation polymerization of dimethyl carbonate (DMC) and 1,4‐butanediol (BD) in the presence of 0.05 mol % sodium alkoxide catalyst. The subsequent feeding of 15 mol % HOAOH, such as 1,6‐hexanediol, 1,5‐pentanediol, 1,4‐cyclohexanedimethanol, or 1,4‐benzenedimethanol and stirring at 190–150 °C converted the extremely thick high‐molecular‐weight polymer to low‐molecular‐weight macrodiols with GPC‐measured Mn ∼2000. The analysis of the 1H NMR spectra indicated that the –A– units and 1,4‐butylene units were randomly distributed in the resulting oligomers. The chopping of the high‐molecular‐weight PBC using either triols or tetraols such as glycerol propoxylate, 1,1,1‐tris(hydroxymethyl)ethane, or pentaerythritol also afforded macropolyols containing branched chains with GPC‐measured Mn ∼2000. When the chopped polymers were genuine PBCs, the resulting macrodiols or polyols were in a waxy state at room temperature. However, permanently oily compounds were obtained when the chopped polymers were prepared using 0.90 mole fraction of BD admixed with various other diols. The macrodiols and polyols synthesized in this study may have potential applications in the polyurethane industry. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 1570–1580 A new method is dislosed for preparation of low‐molecular‐weight macrodiols or polyols (GPC‐measured Mn of ~2000), which have potential applications in the polyurethane industry. Chopping high‐molecular‐weight poly(1,4‐butylene carbonate) or its copolymers (Mn: 40,000–80,000) with a chopper [HOAOH, A(OH)3, or tetraol] in the presence of a small amount of sodium alkoxide catalyst (0.05 mol %) in neat melt conditions at 190–150 °C afforded the desired macrodiol or polyols.