Synthesis and characterization of ordered polyurethanes from nonsymmetric diisocyanate and ethylene glycol

✍ Scribed by Akinori Nishio; Amane Mochizuki; Jun-Ichi Sugiyama; Kazuhiko Takeuchi; Michihiko Asai; Koichiro Yonetake; Mitsuru Ueda

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 193 KB
• Volume: 38
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(20000601)38:11<2106::aid-pola200>3.0.co;2-l

✦ Synopsis

An ordered polyurethane with a head-to-head (H-H) or tail-to-tail (T-T) content over 95% was prepared by polyaddition reaction of a nonsymmetric monomer, p-isocyanatobenzyl isocyanate (1) with a symmetric monomer, ethylene glycol (2). The model reactions were studied in detail to demonstrate the feasibility of polymer formation. The polymerization was conducted in THF in the presence of triethylamine (TEA) at 0 °C by slow addition of a half amount of 2 to 1, followed by removing THF and then adding the rest of 2 in DMF at once at 30 °C in the presence of dibutyltin dilaurate (DBTL). The microstructure of the polymer obtained was investigated by 13 C NMR spectroscopy, and it was found that the polymer had the expected structural regularity. The constitutional regularity of polymers influenced their thermal properties.