摘要:
Described herein is a process for preparing crystalline polyarylates which comprises (a) forming a crystalline polyarylate prepolymer having a reduced viscosity of from 0.05 to about 0.4 dl/g by reacting at least one diester derivative of a dihydric phenol with at least one aromatic dicarboxylic acid in the presence of a solvent, at a temperature of from about 250.degree. to about 300.degree. C., and (b) heating the prepolymer so formed below its melting point to form a crystalline polyarylate having a reduced viscosity of from about 0.45 to about 1.2 dl/g.
摘要:
This invention pertains to novel copolyesters consisting essentially of units (I), (II), (III), and (IV). ##STR1## and blends of these polymers and articles made from both. Units (I), (II), (III), and (IV) are present in specified proportions as defined in the "Description of the Invention."The instant copolyesters display orientation in the molten state, good fiber ratings and high strength. Advantageously, the polymers of the present invention display a significant improvement in viscosity and moldability of the neat polymer. The polymers have excellent mechanical and surface properties including blister resistance, strength, toughness, and ability to vapor phase solder, and form strong fibers while still maintaining a high heat distortion temperature. They have melting points in the range of from about 250.degree. to about 360.degree. C. and are melt-processible. Advantageously, these compositions filled with about 30 weight percent of glass fibers display heat distortion temperatures of up to 240.degree. C., when measured under a load of 264 psi. The polymers may be blended to tailor properties. These polymers and blends may be used advantageously in producing fibers and in electrical equipment, electronic components and other end uses requiring moderately high temperatures.
摘要:
The invention describes a novel process for the preparation of polycarbonate and/or polyarylate block copolymers with poly(aryl ethers). The process is comprised of the steps:(a) the reaction of a dihydroxy-terminated poly(aryl ether) oligomer with a high molecular weight polycarbonate, or a high molecular weight polyarylate, or a high molecular weight poly(arylate-carbonate) to yield a block copolymer; followed by(b) the coupling of the material obtained in step (a) to the required molecular weight, using a diaryl ester of carbonic acid or of a dicarboxylic acid.Both steps are performed in the presence of a catalyst. The copolymerizations can be run in bulk under vacuum in a single or twin screw extruder. Using the above conditions high molecular weight, high quality block copolymers having a combination of excellent properties are obtained in a matter of minutes.
摘要:
The invention describes a novel process for the preparation of polycarbonate and/or polyarylate block copolymers with poly(aryl ethers). The process is comprised of the steps:(a) the reaction of a dihydroxy-terminated poly(aryl ether) oligomer with a high molecular weight polycarbonate, or a high molecular weight polyarylate, or a high molecular weight poly(arylate-carbonate) to yield a block copolymer; followed by(b) the coupling of the material obtained in step (a) to the required molecular weight, using a diaryl ester of carbonic acid or of a dicarboxylic acid.Both steps are performed in the presence of a catalyst. The copolymerizations can be run in bulk under vacuum in a single or twin screw extruder. Using the above conditions high molecular weight, high quality block copolymers having a combination of excellent properties are obtained in a matter of minutes.
摘要:
Novel poly(aryl ether sulfone)-poly(aryl ether ketone) block copolymers are described. They are prepared by the nucleophilic polycondensation of a hydroxy- or halo-terminated poly(aryl ether ketone) oligomer with the poly(aryl ether sulfone) forming reagents; alternatively, a preformed poly(aryl ether sulfone) block may be used.The novel copolymers are tough materials with excellent heat, solvent, and stress-crack resistanced. They display high HDT's (heat distortion temperatures) and are useful in molding, extrusion and composites applications.
摘要:
Described herein are novel poly(aryl ether) polymers that contain naphthalene, terephenylene and/or anthracenylene units within their chains. Representative polymers are tough materials having excellent high temperature, oxidative and chemical resistance, and easy melt fabricability.
摘要:
Described herein are novel block copolymers wherein one block is a poly(aryl ether ketone) oligomer and the other block is a liquid crystalline polyester oligomer. Processes for the preparation of the subject copolymers are also described. The novel block copolymers display excellent mechanical properties, good high temperatures stability and excellent solvent and chemical resistance.
摘要:
Described are novel copolymers of polyphenylene oxides and poly(aryl ether)s. These copolymers are readily compatible with styrene polymers and copolymers and give tough blends.
摘要:
Described herein are polyarylate molding compositions having improved notched izod impact values after molding, which composition comprises a blend of a polyarylate and a siloxane-polyarylene polyether block copolymer and/or a siloxane polycarbonate block copolymer.
摘要:
High molecular weight, thermally stable polyarylates are prepared directly from dihydric phenols, aromatic dibasic acids and a chlorinating agent without isolating an acyl halide intermediate. An organic phosphite can be added to reduce color formation.