摘要:
Copolyimides having good solvent resistance, thermal stability and processability contain about 2-50 mole percent of structural units derived from a tetracarboxybiphenyl, in combination with other structural units typically derived from bisphenol A dianhydride.
摘要:
Injectable composition for desulphurizing molten ferrous metals, especially iron, comprises alkaline earth metal, preferably magnesium, and sintered mixture of lime and at least one fluxing agent. Magnesium is preferably 8 to 60% of composition and lime preferably is 45 to 95% of the sintered mixture. Fluxing agent is preferably alumina and fluoride. Composition enables rapid and efficient desulphurization and does not give large amounts of slag.
摘要:
Compositions which comprise blends of a poly(ester-carbonate) resin and a polyetherimide or a poly(ether sulfone) resin are provided. The compositions are useful for preparing articles that are resistant to autoclave sterilization conditions.
摘要:
A gas turbine engine combustor 20 has a wall structure 22 including an outer wall 24 having a plurality of wall elements 26 attached thereto. Each wall element 26 has a flange 27 around its periphery which defines a chamber 28 between each wall element and the outer wall 24. Holes 30 in the outer wall 24 permit the flow of cooing air into each chamber 28 to provide impingement cooling of the wall elements 26. Holes 30 in the wall elements 26 permit the exhaustion of cooling air from the chambers to provide film cooling of the wall elements 26.
摘要:
Copolyetherimides having random units in the structure and characterized by good transparency after molding are prepared by a process in which a dianhydride and a diamine are reacted at a temperature of at least 100.degree. C. to initiate polymerization, followed by the addition of a second anhydride and continuing the polymerization at the elevated temperature. Preferred features include conducting the reaction in a solvent and in the presence of a chain stopper, such as phthalic anhydride.
摘要:
A fiber optic cable comprising an elongated core about the periphery of which is disposed a plurality of elongated tubes, one or more of the tubes containing elongated optical fibers, at least one elongated filler member ("dummy tube") having essentially the same outside diameter as the tubes containing the optical fibers composed of an elongated core means circumscribed by a coating of plastic containing a multiplicity of void spaces (e.g., foamed plastic) and a plastic jacket circumscribing the tubes and elongated filler member.
摘要:
A composition comprising an aromatic carbonate polymer in admixture with an effective thermal stabilizing amount of a sulfone compound or a sulfonyl containing polymer.