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:
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.
摘要:
Macrocyclic oligomers, including polycarbonates, polyesters, polyamides, polyimides, polyetherketones and polyethersulfones, are conveniently prepared from various spiro(bis)indane compounds, especially the 6,6'-difunctional 3,3',3'-tetramethylspiro(bis)indanes. The macrocyclic oligomers may be conveniently converted to linear polymers.
摘要:
Cyclic polycarbonate mixtures containing units derived from spirobiindane bisphenols, preferably 6,6'-dihydroxy-3,3,3',3'-tetramethylspirobiindane, are prepared from the corresponding bischloroformates or mixtures thereof with bisphenols. They may be homopolymeric or copolymeric; cyclic oligomer mixtures are preferred. Such oligomers may be converted to linear polycarbonates having high glass transition temperatures.
摘要:
Macrocyclic oligomers, including polycarbonates, polyesters, polyamides, polyimides, polyetherketones and polyethersulfones, are conveniently prepared from various spiro(bis)indane compounds, especially the 6,6'-difunctional 3,3',3'-tetramethylspiro(bis)indanes. The macrocyclic oligomers may be conveniently converted to linear polymers.
摘要:
Cyclic polycarbonate mixtures containing units derived from spirobiindane bisphenols, preferably 6,6'-dihydroxy-3,3,3',3'-tetramethylspirobiindane are prepared from the corresponding bischloroformates or mixtures thereof with bisphenols. They may be homopolymeric or copolymeric; cyclic oligomer mixtures are preferred. Such oligomers may be converted to linear polycarbonates having high glass transition temperatures.
摘要:
Bischloroformate compositions are prepared from spirobiindane bisphenols by phosgenation in a substantially inert organic liquid in a two-step reaction. The pH during the first step is maintained in the range of about 8-14 by addition of aqueous base. In the second step, the pH is in the range of about 2-6. This method produces compositions containing a substantial amount of monomeric bischloroformate and avoids gelling problems.
摘要:
Cyclic monocarbonate bischloroformates are prepared by the reaction of a carbonyl halide such as phosgene with a bridged substituted resorcinol or hydroquinone such as bis(2,4-dihydroxy-3-methylphenyl)methane or bis(2,5-dihydroxy-3,4,6-trimethylphenyl)methane in the presence of aqueous alkali metal hydroxide. The cyclic monocarbonate bischloroformates may be used for the preparation of linear or cyclic polycarbonates containing cyclic carbonate structural units, which may in turn be converted to crosslinked polycarbonates.
摘要:
Polycyclic polycarbonate (or thiol analog) oligomers are prepared from a mixture of at least one bishaloformate with at least one tetraphenol, or thio analogs thereof. Such mixture may also contain at least one dihydroxy or dimercapto compound. The oligomers are formed by the reaction of such mixtures with alkali metal hydroxides and various amines. The polycyclic oligomer mixtures may be converted to crosslinked polycarbonates or their thiol analogs.
摘要:
A method is provided for determining the stoichiometric end point of phosgenation reactions which produce polycarbonates and chloroformates, respectively, by monitoring the rate of heat generated by the reaction mixture per unit of phosgene utilized.