Polymers of carbonic acid. XVII. Polymerization of cyclobis(tetramethylene carbonate) by means of BuSnCl3 and Sn(II) 2-ethylhexanoate

✍ Scribed by Hans R. Kricheldorf; Andreas Mahler

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 577 KB
• Volume: 34
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(19960915)34:12<2399::aid-pola14>3.0.co;2-3

✦ Synopsis

Dimeric cyclotetramethylenecarbonate (TeMC)2 was polymerized in bulk at 185OC. Either nBuSnC1, or Sn(II)2-ethylhexanoate (SnOct2) were used as catalysts. SnOct, proved to be somewhat less reactive, but high yields (up to 93%) and high viscosities (qinh up to 0.85 dL/g) were obtained with both catalysts. Viscosity-average molecular weights (M,) in the range of 50-75 X lo3 were determined. The isolated crystalline poly(tetramethy1ene carbonate)s were characterized by IR, 'Hand "C-NMR spectra, DSC measurements and WAXD powder pattern. CH20H and octoate end groups were detected by means of 'H-NMR spectroscopy when SnOct2 was used as initiator, but ether groups were absent. DSC measurements revealed that poly(tetramethy1ene carbonate) is a slowly crystallizing polymer with a degree of crystallinity below 50% and a melting temperature in the range of 64-69°C depending on the molecular weight. Thermogravimetric analyses proved that polyTeMC decomposes completely between 240 and 34OoC without leaving a residue. COP and tetrahydrofuran were the main degradation products. 0 1996 John Wiley & Sons, Inc.