Polymers from renewable resources. XIII. Interpenetrating polymer networksderived 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 varyi ng NCO/OH ratios. All the PUs were reacted with methacrylamide (MAM) using an ethylene glycol dimethacrylate (EGDM) crosslinker and benzoyl peroxide a s an initiator. Thermogravimetric analysis of the polymers was followed usi ng a computer analysis method fur assigning the kinetic mechanism. The degr adation steps are discussed in the light of kinetic parameters. The scannin g electronic microscopy of some of the interpenetrating polymer networks (I PNs) were studied and the morphology was examined, The samples were subject ed to wide-angle X-ray diffraction analysis. Ruland and Vonk's method was u sed to calculate the degree of crystallinity. (C) 2001 John Wiley & Sons, I nc.