Abstract:
An improved method for the preparation of tris(4-hydroxyphenyl) compounds is provided. In particular, an improved method for preparing 1, 1, 1-tris(4'-hydroxyphenyl)ethane is provided which comprises heating a mixture comprising phenol and 4-hydroxy acetophenone in the presence of effective amounts of an ion exchange catalyst and a mercaptan as a copromoter such that the resulting 1, 1, 1-tris(4'-hydroxyphenyl)ethane is substantially free of various reaction impurities.
Abstract:
A method is provided for making polycarbonates utilizing an effective amount of a binary phase transfer catalyst, such as tetrabutylammonium bromide and a methyl tertiary amine as a condensation catalyst during the interfacial phosgenation of a bisphenol, such as bisphenol A. Improved phosgene utilization is achieved.
Abstract:
Polycarbonate-polysiloxane block copolymers are prepared by interfacial polymerization technique in the presence or a phase transfer catalyst.
Abstract:
A thermoplastic composition which comprises a siloxane polycarbonate block copolymer wherein the polysiloxane segments of the copolymer are of the formula: ##STR1## where R.sup.1, R.sup.2, Y, D, A, X, A' and E are as defined herein, and high heat polycarbonates containing recurring or repeating polycarbonate units of the formula: ##STR2## wherein Z is --O--, --N(R.sup.3)-- or a mixture thereof and R.sup.3 is selected from hydrogen, hydrocarbyl and halogen-substituted hydrocarbyl.
Abstract:
A method is provided for making polycarbonate utilizing an effective amount of a phase transfer catalyst, such as tetrabutylammonium bromide as a condensation catalyst during the interfacial phosgenation of a bisphenol, such as bisphenol A. Improved phosgene utilization is achieved.
Abstract:
An aromatic polyphthalatecarbonate resin having a small percentage of phthalate units therein exhibits improved resistance to hazing and yellowing upon exposure to ultraviolet radiation. The polyphthalate carbonate resin is derived from the reaction products of a phthalate compound, a dihydric phenol and a carbonate precursor.
Abstract:
Novel compositions comprising a high concentration of poly(2,6-benzothiazole) and certain polyphosphoric acids are prepared. Such compositions are optically anisotropic (liquid crystalline), capable of exhibiting excellent cohesive strength, and are especially suited to the production of high molecular weight ordered polymer fibers by dry-jet wet spinning. These liquid crystalline compositions are capable of being drawn through long air gap distances and spun at exceptionally high spin draw ratios. Fibers, films and other articles formed from these liquid crystalline compositions exhibit exceptionally high physical and heat resistant properties.
Abstract:
A poly(siloxane) copolymer composition comprising: a first polymer comprising a first repeating unit, and a poly(siloxane) block unit, a second polymer different from the first polymer and comprising of bromine; and optionally, one or more third polymers different from the first polymer and second polymer; wherein siloxane units are present in the composition in an amount of at least 0.3 wt %, and bromine is present in the composition in an amount of at least 7.8 wt %, each based on the sum of the wt % of the first, second, and optional one or more third polymers; and further wherein an article molded from the composition has an OSU integrated 2 minute heat release test value of less than 65 kW-min/m2 and a peak heat release rate of less than 65 kW/m2, and an E662 smoke test Dmax value of less than 200.
Abstract translation:一种聚(硅氧烷)共聚物组合物,其包含:包含第一重复单元的第一聚合物和聚(硅氧烷)嵌段单元,不同于第一聚合物并包含溴的第二聚合物; 和任选的一种或多种不同于第一聚合物和第二聚合物的第三聚合物; 其中硅氧烷单元以至少0.3重量%的量存在于组合物中,并且溴以至少7.8重量%的量存在于组合物中,各自基于第一,第二, 和任选的一种或多种第三聚合物; 并且其中由所述组合物成型的制品具有小于65kW-min / m 2的OSU集成的2分钟的热释放试验值和小于65kW / m 2的峰值放热率,以及E662烟雾试验Dmax值 小于200。
Abstract:
There is provided herein an optical storage media which has low VBR. In a preferred embodiment, there is provided an optical disk comprising a genus of copolycarbonates, including copolyestercarbonates, which have excellent physical and optical properties. Said copolycarbonates have proportions of structural units which fall within a specific composition range, and said range defines certain materials, a large percentage of which can be molded into optical disks having the desired optical properties, including low VBR.
Abstract:
Terpolymers suitable as molding resins are provided having aromatic polyester segments polycarbonate segments and polysiloxane segments of the structure ##STR1## where R.sup.1, R.sup.2, Y and D are as defined herein, and where the weight percentage of polyester and polycarbonate segments is from 50 to 99%, preferably 92 to 96%, and the weight percentage of polysiloxane segments is from 50 to 1%, preferably from 8 to 4%. Also provided is a one-step process to prepare the new terpolymers by reacting together a siloxane, a bisphenol and an aromatic dicarboxylic acid halide.