Novel binary blends of polyarylacetylene (PAA resin) with propargyl-novoalc resin (PN resin) was prepared. The miscibility, processing capability, and thermal properties of the blends were investigated. The evaluation of the blends as matrice for thermostructural composites was also studied. The blends were highly miscible. In comparison to PAA resin, the blends exhibited remarkably improved processability suitable to various process techniques (especially resin transfer molding, RTM). By dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA), it was revealed that the cured blends possessed high thermal stability. The blend with 1/2 PN content was evaluated as matrices. The high temperature mechanical properties of silica laminates were compared favorably with those of conventional phenolic laminate. When compared with pure PAA laminate, the blend matrix laminate exhibited improved mechanical properties at both ambient temperature and high temperature. (C) 2007 Wiley Periodicals, Inc.