SYNTHESES AND PROPERTIES OF AB CROSS-LINKED POLYMERS - VINYL-TERMINATED POLYURETHANES ALLYL NOVOLAC RESIN

The AB cross-linked polymers (ABCPs) based on vinyl-terminated polyure thane [derived from polyurethane (PU) prepolymer with methacrylamide] and allyl novolac resin (obtained by substituting the hydrogen of hydr oxy group of phenol in novolac resin with the allyl group) were synthe sized. The PU prepolymer was composed of 4,4'-diphenylmethane diisocya nate (hard segment) and poly(tetramethylene oxide) (soft segment). For these ABCPs, phase mixing was investigated and evaluated through dyna mic mechanical analysis, differential scanning calorimetry, and transm ission electron microscopy. The results indicated that the compatibili ty between PU and phenolic resin was improved, but there is no well-de fined relationship in the mechanical properties. (C) 1996 John Wiley & Sons, Inc.