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Effect of processing variables on the thermophysical properties of polybenzimidazole foams
Author(s) -
Kourtides Demetrius A.,
Parker John A.
Publication year - 1975
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760150604
Subject(s) - materials science , composite material , prepolymer , curing (chemistry) , thermal conductivity , thermal diffusivity , porosity , thermal insulation , polyurethane , thermodynamics , physics , layer (electronics)
Polybenzimidazole foams in the density range of 24 to 80 kg/m 3 have excellent thermophysical properties, fire resistance, and low smoke evolution when exposed to heat or flame; they also retain their mechanical properties up to 200°C without any significant degradation. In addition to superior thermal properties, the foams maintain a high degree of flexibility and a good modulus‐to‐weight ratio, as well as high strength‐to‐weight relationship at high temperatures. These properties make this foam an attractive candidate as a low‐weight, high‐temperature insulation for aerospace applications. This paper describes the relationship between prepolymer purity, processing parameters, and additives to the thermophysical and chemical properties of these foams. Foam properties are shown to be affected by differences in prepolymer purity, curing schedule, and the presence of additives in the foam. High‐temperature compressive properties were imporved by postcuring at 527°C. Surfactant additives were found to improve uniformity of cell size. Foams were characterized according to high‐temperature mechanical properties, density, porosity, thermal diffusivity, thermal conductivity, and specific heat.