Phase Structures of Hexamine Cross-Linked Novolac Blends. 1. Blends with Poly(methyl methacrylate)

Abstract

The miscibility and phase structures of initially miscible novolac/poly(methyl methacrylate) (PMMA) blends after full curing of the novolac are investigated by high-resolution solid-state NMR, FT-IR, and DSC techniques. The strong intermolecular hydrogen-bonding interaction between novolac and PMMA results in the blends being miscible at the molecular level, and the phase-separation process of the blends is very slow even at 200 °C. Curing novolac/PMMA blends with hexamine reduces the intermolecular hydrogen bonding significantly, but a considerable amount of residual intermolecular hydrogen bonds still remains in the cured blends. The phase structures of the fully cured novolac/PMMA blends ..