Polymers from renewable resources. XIII. Interpenetrating polymer networks derived from castor oil–hexamethylene diisocyanate and polymethacrylamide



Several castor oil-based polyurethanes (PUs) samples were synthesized using various diisocyanates such as hexamethylene diisocyanate (HMDI) with varying NCO/OH ratios. All the PUs were reacted with methacrylamide (MAM) using an ethylene glycol dimethacrylate (EGDM) crosslinker and benzoyl peroxide as an initiator. Thermogravimetric analysis of the polymers was followed using a computer analysis method for assigning the kinetic mechanism. The degradation steps are discussed in the light of kinetic parameters. The scanning electronic microscopy of some of the interpenetrating polymer networks (IPNs) were studied and the morphology was examined. The samples were subjected to wide-angle X-ray diffraction analysis. Ruland and Vonk's method was used to calculate the degree of crystallinity. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1349–1353, 2001