Effect of matrix chemical structure on the thermo‐oxidative stability of addition cure poly(imide siloxane) composites

Abstract

A series of addition cure poly(imide siloxane) resins were synthesized, incorporating various concentrations of α, ω‐bis(3‐aminopropyl) poly(dimethyl‐diphenylsiloxanes), and α, ω‐bis(p‐aminophenyl) poly(dimethylsiloxane) into the formulated imide oligomer. Both carbon and glass fiber textile laminates were fabricated using amic acid and polymerization of monomer reactants (PMR) approaches. The cured composite laminates were subjected to an accelerated thermo‐oxidative aging environment of 400°C for 100 h in air. Physical, thermal, and mechanical properties were evaluated to determine the structure‐oxidative stability interrelationships. In general, composite mechanical properties were found to increase with increasing siloxane concentration in the matrix. Composite thermo‐oxidative durability (measured via mass loss and mechanical property retention after oxidative aging) was improved through incorporation of diphenyl and diphenyl‐dimethyl siloxane segments into the imide oligomer backbone up to ∼35% by weight aminosiloxane. Oxidative stability was found to be mostly dependent on the degree of phenyl substitution on the silicon atoms in the siloxane blocks, as compared to the moiety attaching the amine groups to the siloxane block. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers

Oxidatively stable thermosets derived from thermal copolymerization of acetylene-terminated imide monomer with an acetylenic monomer containing carborane

“…Many studies have been carried out to improve thermal and thermo-oxidative stability of polyimide materials over the recent years, and making the polymer structure organic/inorganic hybrid has been proved to be effective. [5,[11][12][13] Icosahedral carboranes, carbon-containing polyhedral boron-cluster compound, have special thermal stability because of their stable cage structures and rich boron contents. [14][15][16][17][18][19][20] Polymers containing the carborane unit within the backbone exhibit appreciable enhancement in their oxidative stability, and numerous polymers containing carborane cage structures have been reported, such as poly(ether ketone)s, polythiophenyls, polysiloxanes and polysilanes.…”

Self‐catalyzed silicon‐containing phthalonitrile resins with low melting point, excellent solubility and thermal stability

“…Meanwhile, T g is a very important parameters and estimated on the basis of the peak temperatures tan δ curves. Since there is no peak found in the tan δ curves of all the samples in the measured temperature range (Figure ), it can be concluded that all the cured SiPNs possess T g above 450°C …”

“…Meanwhile, T g is a very important parameters and estimated on the basis of the peak temperatures tan d curves. Since there is no peak found in the tan d curves of all the samples in the measured temperature range (Figure 9), it can be concluded that all the cured SiPNs possess T g above 450 C. 32,34,35 CONCLUSIONS A series of SiPNs were prepared and characterized. The monomers can be thermally polymerized in the absence of any catalysts.…”

Carborane-Containing Aromatic Polyimide Films with Ultrahigh Thermo-Oxidative Stability

“…However, the mismatching of the coefficient of thermal expansion (CTE) between inorganic coatings and polymer matrices might result in serious troubles such as delamination, curl, or crack after harsh heat shocking [28]. Although the addition of inorganic fillers into polymer matrices to form hybrid structures is an effective pathway in enhancing thermo-oxidative stability of polymer materials, the limited filler loadings and the poor miscibility of inorganic fillers and organic matrices are the big issues [26,27,29,30]. Hence, developing intrinsic thermo-oxidative stable polymers is still the desirable pathway.…”