Synthesis and properties of maleimide-terminated polyurethane AB crosslinked polymers - I. Polyurethane allyl nonyl novolac resin ABCPs

Polyurethane (PU) and phenolic resin were prepared to form maleimide-termin ated PU/allyl nonyl novolac resin ABCPs. The polyurethane was prepared from 4,4'-diphenyl methane diisocyanate (MDI) and poly(tetramethylene oxide) [P TMO] of various molecular weights. The composition, compatibility, mechanic al and thermal properties of these inhomogeneous network polymers were inve stigated through differential scanning calorimetry (DSC), dynamic mechanica l analysis (DMA), the tensile strength tester and transmission electron mic roscopy (TEM) micrographs. The results reveal that the miscibility makes on ly a little improvement but the tensile strength has clear improvement when the PU's soft segment, i.e. PTMO, is higher, because of the entanglement b etween components. (C) 1999 Elsevier Science Ltd. All rights reserved.