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Synthesis and characterization of castor‐oil‐modified hyperbranched polyurethanes
Author(s) -
Karak Niranjan,
Rana Sravendra,
Cho Jae Whan
Publication year - 2009
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.29468
Subject(s) - polymer , castor oil , branching (polymer chemistry) , materials science , polymer chemistry , gel permeation chromatography , crystallization , polyurethane , ethylene glycol , diol , condensation polymer , fourier transform infrared spectroscopy , chemical engineering , organic chemistry , chemistry , composite material , engineering
A series of castor‐oil‐modified hyperbranched polyurethanes were synthesized via an A 2 + B 3 approach based on castor oil, macroglycol poly(ϵ‐caprolactone)diol or poly(ethylene glycol) (PEG), and diphenyl methane diisocyanate, with or without a chain extender. The yield of the product was 95%, and the polymers were soluble in common organic polar solvents. The synthesized polymers were characterized with Fourier transform infrared spectroscopy, NMR, wide‐angle X‐ray diffraction, and gel permeation chromatography measurements. The degree of branching of the polymers was calculated from their respective 1 H‐NMR spectra with the help of model compounds and found to be varied from 0.7 to 0.8. The hard‐segment content, the nature of the macroglycol, and the composition of the polymers had prominent effects on the thermal degradation and crystallization of the hyperbranched polymers. The crystallization of poly(ϵ‐caprolactone) and PEG as soft segments occurred well in the hyperbranched polymers. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009