Preparation and properties of silicon-containing arylacetylene resin/benzoxazines blends

A series of aniline-based bifunctional benzoxazines (BZs) were synthesized using solventless or solvent method via the Mannich condensation reactions. The chemical structures of these BZs were confirmed using Fourier-transform infrared and proton-nuclear magnetic resonance spectroscopies. The polymer blends were prepared by mixing silicon-containing arylacetylene (poly(dimethylsilyleneethynylenephenyleneethynylene) (PSA)) resin with BZ in weight ratios at 110 degrees C until a homogeneous viscosity liquid was obtained. The resultant blends were characterized by solubility tests, rheological analyses, differential scanning calorimetry, dynamic mechanical analyses and thermogravimetric analyses. The good solubility and low melt viscosity of the blends indicated excellent processability. The curing reactions resulted in the formation of interpenetrating polymer networks. The cured blends exhibited high glass transition temperatures (T(g)s) and thermal stabilities. The compressive strength and flexural strength of the blend casts improved when compared with pristine PSA.