摘要:
A method for preparing a polyestercarbonate copolymer using solid state polymerization and polyestercarbonates prepared thereby is described. The method comprises preparing a mixture comprising partially crystalline bisphenol A polycarbonate oligomer and hydroxy acids, aliphatic diacids, cycloaliphatic diacids, aromatic diacids or aromatic triacids and subjecting that mixture to solid state polymerization to afford a polyestercarbonate copolymer.
摘要:
Methods for continuous bulk production of polyolefin polyhedral oligomeric silsesquioxanes and their amino, isocyanate, and alcohol derivatives using silane coupling agents as precursors.
摘要:
The present invention discloses a vapor phase method of introducing a branching agent such as THPE into a solid polycarbonate while simultaneously crystallizing the solid polycarbonate. The partially crystalline polycarbonate containing a branching agent introduced in this manner is suitable for use in the preparation of branched polycarbonates by solid state polymerization. Branching in the polycarbonates so produced is demonstrated by rheometric measurements. Such branched polycarbonates are known to possess increased material melt strength, shear sensitivity, and complex viscosity ratio, and are particularly well-suited in blow molding applications.
摘要:
Aliphatic tricarboxylic acids, as exemplified by 9-carboxy-1,18-octadecanedioic acid, may be prepared by the biotransformation of an olefinic monocarboxylic acid such as oleic acid to the corresponding olefinic dicarboxylic acid, preferably 1,18-octadec-9-enedioic acid, in the presence of a strain of yeast, such as a strain of Candida tropicalis, followed by the carboxylation of the olefinic dicarboxylic acid by reaction with carbon monoxide and water in the presence of a catalyst. The product tricarboxylic acids are useful as branching agents for polycarbonates.
摘要:
Polycarbonate copolymers have been prepared by solid state polymerization (SSP). A mixture comprising partially crystalline BPA polycarbonate oligomer having a weight average molecular weight of 10,000 daltons and a source of additional structural units and optionally a catalyst is reacted under SSP conditions to afford a copolycarbonate. Sources of additional structural units include high and low molecular weight polycarbonates incorporating repeat units not derived from BPA and various bisphenols such as BPI, BPM and tetramethyl BPA.
摘要:
The present invention discloses improved copolycarbonates and methods for their synthesis that involve the incorporation of aliphatic diol carbonates into copolycarbonate chains under solid state polymerization conditions. More particularly, the present invention utilizes diphenyl carbonate in the production of copolycarbonates that exhibit modified thermal properties(lower Tg) relative to analogous simple copolycarbonates. The solid sate polymerization technique possesses a distinct advantage over melt polymerization in that no specialized melt polymerization equipment is required.
摘要:
A method of crystallizing an aromatic polycarbonate prepolymer having a molecular weight of from about 1,000 to about 20,000 and having from about 5 to about 95 mole % aryl carbonate terminal end groups, based on total end groups, the method comprising effecting contact of the prepolymer with a crystallizing agent comprising an alcohol and an additive, wherein the additive is effective to increase the rate of solid state polymerization.
摘要:
The invention relates to a method of crystallizing an aromatic polycarbonate prepolymer having a molecular weight of from about 1,000 to about 20,000 and having from about 5 to about 95 mole % aryl carbonate terminal end groups, based on total end groups, the method comprising effecting contact of the prepolymer with a crystallizing agent comprising an alcohol, preferably, at least 95% by weight of an alcohol.
摘要:
This invention involves a novel process for preparing branched polycarbonates employing a solid state polycondensation process; specifically, subjecting a linear crystallized oligomer derived from dihydroxydiaryl compound and a diaryl carbonate to solid state polycondensation process by heating the said oligomer at a temperature which is higher than the glass transition temperature but below its melting point in the presence of a multifunctional phenol and an alkali or alkaline metal salt or bisphenol or tetraalkylammonium hydroxide, carboxylate or bicarboxylate catalyst, the reaction being effected under inert atmosphere.
摘要:
Methods for continuous bulk production of polyolefin polyhedral oligomeric silsesquioxanes and their amino, isocyanate, and alcohol derivatives using silane coupling agents as precursors.