摘要:
A process for preparing a thermoplastic, randomly branched aromatic polycarbonate is disclosed which comprises reacting a carbonate precursor, a dihydric phenol, and a dianhydride branching agent and maintaining the resultant reaction medium at a pH of from about 9 to about 12 to thereby produce a thermoplastic randomly branched aromatic polycarbonate.
摘要:
Cyclic polycarbonate (or thiol analog) oligomer mixtures are prepared by the reaction of bishaloformates or their thio analogs, or mixtures thereof with dihydroxy or dimercapto compounds, with alkali metal hydroxides and various amines. The oligomer mixtures may be converted to polycarbonates or their thiol analogs by a method which is particularly adaptable to integration with polycarbonate processing operations. Polymerization may be conducted simultaneously with molding, extrusion and the like. The oligomer mixtures are adaptable to the preparation of filled prepregs.
摘要:
An embodiment assembly for the impregnation of a continuous length of fibers comprises a convex surface and a non-convex surface over which the length of fibers is drawn under tension. The pressure of impingement on the surfaces alternately separates and consolidates the fibers in sequence during their impregnation with the resin, to obtain a complete and homogeneous impregnation.
摘要:
Thermoplastic randomly branched copolyester-carbonate resin containing from about 40 mole percent to about 90 mole percent ester bonds which is particularly suited for blow molding operations. This branched copolyester-carbonate resin is obtained by reacting a carbonate precursor, at least one dihydric phenol, at least one ester forming reactive derivative of a difunctional carboxylic acid, and a polyfunctional aromatic branching agent.
摘要:
Apparatus and method for the impregnation of a continuous length of multifilament or multifiber yarns with a molten thermoplastic polymeric resin includes a member for spreading the multifilaments or multifibers apart during their immersion in a bath of the molten resin. The shape, configuration and location of the member facilitates the homogeneous impregnation, particularly with highly viscous melts, to produce a uniform and thorough encapsulation of the filaments or fibers.
摘要:
Apparatus for the impregnation of a continuous length of multifilament or multifiber yarns with a molten thermoplastic polymeric resin includes a pair of convex/concave (mating) surfaces for spreading the multifilaments or multifibers apart during their immersion in a bath of the molten resin. The shape, configuration and location of the surfaces facilitates homogeneous impregnation, particularly with highly viscous metls, to produce a uniform and thorough encapsulation of the filaments or fibers.
摘要:
Apparatus and method for the pultrusion of polymeric resins reinforced with continuous lengths of multifilaments and/or fibers comprises wetting the lengths of multifilaments and/or fibers with a polymerization initiator, passing the wet length through an impregnating bath of a resin prepolymer and activating the polymerization in-situ.
摘要:
A process is disclosed for isolating and purifying diphenol by-products to obtain an enriched chroman-I concentrate. The process includes slurrying a mixture of diphenol by-products in a suitable solvent system to form a solid, and then recovering, washing and drying the collected solid.
摘要:
A sizing and/or forming die is employed in the pultrusion of filament or fiber reinforced thermoplastic resins such as polycarbonates. The die is adjustable on-line to change the ratio of resin to reinforcement at will and without interrupting the production process.
摘要:
A new aromatic copolyestercarbonate is achieved with 70 to 95 weight percent ester content and having consistently high 3.2 mm impact strength while maintaining a high level of stress cracking resistance.