Thermally/chemically resistant glassy carbon articles - by shaping, curing, and heat treating mixture of polyacetylenic aromatic cpd, and liquidizer

摘要

Glassy carbon articles e.g. extrudates and mouldings, are produced by (a) forming a mixt. of (I) a prepolymer of a polyacetylenic aromatic cpd. esp. diethynylbenzene and (II) a liquidiser for (I), (b) converting the mixt. to the desired shape at 40-200 degrees C, (c) heating the shaped mixt. at 100-300 degrees C in order to cure the mixt. and (d) converting the cured mixt. into the glassy carbon state by heating in an inert atmos. at a temp. increasing progressively to a value between 450 degrees C and 3000 degrees C. (I) has an av. mol. wt. of 900-12,000 a ratio of aromatic protons to olefinic protons 2.4, and contains 5-20 wt. % acetylenic groups, relative to wt. of prepolymer. There is no release of gas during the curing operation which can be effected simply by heating. The cured pdts are hard, rigid, resistant to abrasion, infusible and insoluble, resistant to attack under oxidising conditions at elevated temp. and resistant to attack by strong acids and conc. alkalis.