摘要:
In accordance with a preferred embodiment of this invention, a family of alkylene-linked aromatic polyimides is synthesized. These polymers are thermally stable at a temperature of at least 400.degree. C. and processible in conventional thermoplastic processing equipment. Such new and useful polymers are produced by employing an alkylene-linked dixylene which is oxidized and dehydrated to form the corresponding dianhydride. This alkylene-linked dianhydride is then reacted, through a condensation polymerization reaction, with any of many known diamine terminated compounds to form the subject polyimide resins.
摘要:
A process for the formation of a purified anhydrosugar alcohol is disclosed, whereby the resultant purified anhydrosugar alcohol has a purity of at least 99.8% and is substantially colorless. The anhydrosugar alcohol is purified by distillation, recrystallization from methanol, ethanol or ethylene glycol, melt recrystallization, or a combination thereof. Preferably, the purification is by distillation followed by recrystallization from methanol, ethanol or ethylene glycol. A test for determining the purity of the anhydrosugar alcohol is disclosed, wherein the color of the anhydrosugar alcohol after annealing at a temperature of at least 260° C. for at least four hours is examined. Alternatively, purity can be determined by examination of ultraviolet (UV) transmittance of the purified anhydrosugar alcohol at various wavelengths. The purified anhydrosugar alcohol may be incorporated into a polymer such as a polyester, which may in turn be used to form such articles of manufacturing as containers, optical disks, fibers, sheets and films.
摘要:
An optical article made of a transparent polymer which includes terephthaloyl moieties, optionally, other aromatic diacid moieties; ethylene glycol moieties; isosorbide moieties; and, optionally, one or more other diol moieties, wherein the polymer has an inherent viscosity of at least about 0.35 dL/g as measured on a 1% solution (weight/volume) in o-chlorophenol at 25.degree. C.
摘要:
An isotropic polyester polymer and method for making the polyester is prepared by (1) combining in a reactor a monomer containing a terephthaloyl moiety; optionally, one or more other monomers containing an aromatic diacid moiety; a monomer comprising an ethylene glycol moiety; a monomer containing an isosorbide moiety; optionally, one or more other monomers containing a diol moiety; and optionally, a monomer containing a diethylene glycol moiety; with a condensation catalyst suitable for condensing aromatic diacids and glycols; and (2) heating the monomers and catalyst to polymerize the monomers to yield a polyester having an inherent viscosity of at least about 0.35 dL/g.
摘要:
A melt processable poly(ester-amide) which is capable of forming an anisotropic melt phase is provided. A poly(ester-amide) of the present invention may have recurring units of: (a) 4-hydroxybenzoyl moiety, (b) 6-oxy-2-naphthoyl moiety, (c) 4,4'-biphenol moiety, (d) terephthaloyl moiety, and (e) an aromatic moiety capable of forming an amide linkage in the proportions indicated. Preferably, the moiety capable of forming an amide linkage is derived from p-aminophenol, p-phenylenediamine, N-acetyl-p-aminophenol, etc. The resulting poly(ester-amide) is capable of undergoing melt-processing in the temperature range of from about 300.degree. to about 400.degree. C.
摘要:
The present invention discloses a wholly aromatic, melt processable polyester which is comprised of recurring moieties derived from the following compounds: 2,6-naphthalenedicarboxylic acid, 4-hydroxybenzoic acid, an aromatic dihydroxy compound, and 6-hydroxy-2-naphthoic acid. The resulting wholly aromatic polyester is capable of forming a thermotropic melt phase at temperatures below approximately 350.degree. C. and most preferably at temperatures below approximately 290.degree. C.
摘要:
A process for preparing polyarylates having low color wherein isophthalic acid, terephthalic acid, and bisphenol A are melt polymerized to form a prepolymer, the prepolymer is crystallized, and then further polymerized in the solid state by heating under an inert gas flow, e.g. nitrogen. Crystallization is accomplished by adding the amorphous prepolymer in powder or pellet form to a organic crystallizing medium such as 2-ethoxyethyl acetate or hexyl acetate. This process produces a polymer having low color content. The crystallized polymer may be made amorphous by melting. This amorphous polymer is useful in applications requiring a transparent, colorless plastic.
摘要:
Melt extruded poly(6-oxy-2-naphthoate-4-oxybenzoate) shaped articles of relatively high strength and modulus are produced in a lesser period of time than commonly heretofore required in the prior art. The required polymer is capable of exhibiting an anisotropic melt phase and is formed through the reaction of 6-acetoxy-2-naphthoic acid and 4-acetoxybenzoic acid under a combination of melt polymerization conditions which surprisingly has been found to yield a shaped article following melt extrusion which may be heat strengthened in an unusually brief period of time (i.e. two hours or less). The polymerization is catalyzed by a potassium salt (e.g. potassium acetate), and the polymerization conditions require a relatively highly elevated final polymerization temperature. Substantially all of the acetic acid by-product is removed from the polymerization zone prior to concluding the polymerization under reduced pressure conditions. The process of the present invention through the reduction of the required heat strengthening time accordingly makes possible a substantial productivity increase for a given production facility.
摘要:
The novel polyester of the present invention is capable of forming an anisotropic melt phase and may be prepared on a relatively economical basis. Such polyester includes a relatively low concentration of 6-oxy-2-naphthoyl moiety in combination with a more substantial concentration of 4-oxybenzoyl moiety. Other key moieties present are 4,4'-dioxybiphenyl moiety and terephthaloyl moiety. The polyester has been found to be capable of undergoing melt extrusion at a sufficiently low temperature to form quality high performance fibers, films, and three-dimensional shaped articles. Such product surprisingly has been found to be capable of exhibiting unusually high modulus characteristics in combination with other desirable properties.
摘要:
Provided is a method for preparing aromatic copolyesters of hydroxy naphthoic acid and hydroxy benzoic acid via an in situ esterification technique whereby there is no isolation of the esterified monomers. The process comprises reacting the aromatic hydroxy acid monomers with an agent such as acetic anhydride in order to esterify the hydroxy moieties and subsequently polymerizing the esterified hydroxy monomers without isolation thereof, all in the presence of from about 5 to 50 ppm iron. Advantageously, the process allows one to obtain a wholly aromatic polyester of high inherent viscosity and good melt stability while avoiding the time consuming step of having to isolate the esterified hydroxy monomers prior to polymerization.