摘要:
A method of preparing block copolymers by solid state polymerization is described. A mixture of a partially crystalline polycarbonate having activated terminal aryloxy groups, for example terminal methyl salicyl groups, when heated together with an oligomeric polyester having reactive terminal hydroxy groups under solid state polymerization conditions affords block copolymers. The activated terminal aryloxy groups play a key role in preserving the block lengths of the starting materials. A control sample in which the partially crystalline polycarbonate lacks activated terminal aryloxy groups, for example polycarbonates substituted by phenol, affords a much lower molecular weight, more highly randomized copolymer product. The product block copolymers are useful as “weatherable” plastic materials.
摘要:
The present invention describes the incorporation of several types of soft-block materials into resorcinol phthalate-co-polycarbonate polymers. In preferred embodiments, the soft-block materials contain aliphatic moieties or silicones as flexibilizing units. Several methods of incorporation into the copolymer structure are described including co-reaction of diols with iso/terephthaloyl chloride, replacement of the normal chainstopper with a p-alkylphenol, replacement of a portion of the bisphenol A with an aliphatic ester-bisphenol, and co-reaction of aliphatic diacid chlorides. The polymers of the present invention have good flow characteristics at temperatures generally used for coating, and have good thermostability and weatherability.
摘要:
Oxybisphthalic compounds such as 4,4'-oxybis(N-methylphthalimide) and 4,4'-oxybis(phthalic anhydride) are prepared from the corresponding nitro- or halo-substituted phthalic compounds by reaction with an alkanoate or carbonate salt in a non-polar solvent and in the presence of a hexaalkylguanidinium salt as phase transfer catalyst. A carboxylic acid such as 4-chlorobenzoic acid may be used as an additional catalyst. Reaction rates and yields are higher than with other phase transfer catalysts.
摘要:
High flow brominated polycarbonates, useful as flame retardant additives for other polymers such as polyesters, are obtained by equilibration of a brominated aromatic polycarbonate such as a tetrabromobisphenol A homo- or copolycarbonate with a di- or polyhydroxy aromatic compound such as bisphenol A, or a diaryl carbonate, and an equilibration catalyst, under conditions such that the weight average molecular weight of the brominated polycarbonate is reduced by at least 35%. Preferred equilibration catalysts are Group I metal carboxylates, such as sodium stearate, and hexaalkylguanidinium salts.
摘要:
Copolyetherimides are prepared by the reaction of an alkali metal salt of a dihydroxyaromatic compound with a bis(substituted phthalimide) and a third compound which may be a substituted aromatic ketone or sulfone or a macrocyclic polycarbonate or polyarylate oligomer. The reaction takes place the in presence of a solvent and a phase transfer catalyst having high thermal stability, such as a hexaalkylguanidinium halide. Random or block copolymers may be obtained, depending on the reaction conditions.
摘要:
Macrocyclic polyester oligomer compositions are polymerized to high molecular weight polyesters by heating with a titanate ester composition comprising moieties having oxygen or nitrogen chelated with a titanium atom or having two titanium atom connected by alkylene ester units. Depending on the chemical nature of the initiator, the polymerization reaction may be extremely rapid as desired for structural reaction injection molding, or may have an induction period as desired for resin transfer molding.
摘要:
Polyether polymers, such as polyetherimides, are prepared by the reaction of a dihydroxy-substituted aromatic hydrocarbon alkali metal salt, such as bisphenol A disodium salt, with a bis(N-(chlorophthalimido))aromatic compound, such as 1,3- and/or 1,4-bis(N-(4-chlorophthalimido))benzene, in a solvent such as o-dichlorobenzene and in the presence of a phase transfer catalyst such as a hexaalkylguanidinium chloride. Several embodiments may be employed to improve the method. They comprise employing substantially dry reagents, employing a high solids level in solvent, beginning with an excess of bis(N-(chlorophthalimido))-aromatic compound and incrementally adding alkali metal salt, employing alkali metal salt of small particle size, and using reagents of high purity.
摘要:
Thermally stable polymers comprising resorcinol arylate chain members are prepared using an interfacial method comprising the steps of: (a) combining at least one resorcinol moiety and at least one catalyst in a mixture of water and at least one organic solvent substantially immiscible with water; and (b) adding to the mixture from (a) at least one dicarboxylic acid dichloride while maintaining the pH between 3 and 8.5 through the presence of an acid acceptor, wherein the total molar amount of acid chloride groups is stoichiometrically deficient relative to the total molar amount of phenolic groups.
摘要:
High yields of ester-substituted diary carbonates such as bis-methyl salicyl carbonate were obtained by the condensation of methyl salicylate with phosgene in the presence of a phase transfer catalyst (PTC) in an interfacial reaction system in which the pH of the aqueous phase was greater than 9.3. Using the method of the present invention conversions of greater than 99% were obtained whereas under standard conditions using triethylamine as the catalyst conversions were limited to 70-75% of the methyl salicylate starting material even with a 20 mole % excess of added phosgene. The optimized conditions of the of the present invention use only a slight excess of phosgene and represent an attractive route for the manufacture of bis methyl salicyl carbonate and ester-substituted diaryl carbonates generally.
摘要:
A method of preparing a telechelic ionomeric polyester includes reacting a first diol with a sulfoaromatic carboxylic acid salt to form a sulfoaromatic carboxylate ester salt, and reacting the sulfoaromatic carboxylate ester salt with a diester and a second diol in the presence of a transesterification catalyst to form a telechelic ionomeric polyester. Also disclosed are telechelic ionomeric polyesters.