Self-Organized Thermosets: Blends of Hexamethyltetramine Cured Novolac with Poly(2-vinylpyridine)-block-poly(isoprene)

We demonstrate a concept to prepare thermally cross-linked nanostructured phenolic resins based on self-organization. Novolac, containing hexamethyltetramine (HMTA) as a curing agent, is blended with poly(2-vinylpyridine)- block -poly(isoprene), P2VP- block -PI, where the block length of P2VP has been selected to be sufficiently high to allow the mutually hydrogen-bonded novolac and P2VP, including HMTA, to be contained in the same microphase-separated domains. The novolac-containing domains have subsequently been cross-linked by thermal curing. By tailoring the block lengths, we demonstrate lamellar, cylindrical, and spherical cross-linked phases using transmission electron microscopy. The concept opens simple schemes to modify properties of common phenolic thermosets.