Mechanical and thermal properties of epoxypolymethyl methacrylate blends synthesizedin supercritical carbon dioxide

A series of epoxy/polymethyl methacrylate (E/PMMA) blends was synthesized through impregnation polymerization of methyl methacrylate at concentrations ranging (0–1.5 phr) into diglycidyl ether of bisphenol‐A (0.1 mol) in presence of 2,2‐azobisisobutyronitrile (2 × 10 −2 mol) at 3000 psi, (60–90 ± 1)°C for 3 h in supercritical carbon dioxide, followed by curing of treated epoxy with triethylene tetramine (10 phr) at (40 ± 1)°C. The progress of all such impregnation polymerization reactions was monitored rheoviscometrically. Formation of E/PMMA blends was ascertained through of PMMA mass uptake (%) into epoxy, UV–vis and FTIR spectra, and TEM. With PMMA mass uptake (%), compression strength and resistance against wear of E/PMMA blends were increased with simultaneous decrease in their Rockwell hardness (R scale), charpy impact, and tensile strength, respectively. All E/PMMA blends have shown nonuniform photoelastic behavior at applied load ranging 4–20 kgf and significant stability against thermooxidation with T g / T m and char yield (%) ranging 0.53–0.59, 29.31–31.66, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1303–1310, 2007