Abstract: A polyamide composition comprising an aliphatic polyamide such as nylon 6 and an oligomeric aromatic polyamide, such as oligomers of poly(tolylene diisophthalamide), which exhibit improved retention flexural modulus and flexural strength at ambient humidity, i.e. about 50% to about 65%.

Abstract: This invention relates to an improved polyester composition that has a wide temperature range of crystallization. The composition comprises a polyester and a chemically reacting crystallization modifier having the following formula:H.sub.2 N--R.sup.1 --O--(R.sup.2 --O).sub.x --R.sup.3 --NH.sub.2whereinR.sup.1 and R.sup.3 are independently selected from the group consisting of alkylene units having from about 2 to about 6 carbon atoms;R.sup.2 is a hydrocarbon radical of 2-6 carbon atoms; andx is from 1 to 100.

Abstract: A process of preparing homopolymers and copolymers of dodecane terephthalamide having a high melting temperature and dimensional stability, comprising the steps of forming an aqueous suspension of a prepolymer comprising substantially equimolar diacid/diamine admixture of 1,12-dodecanediamine, terephthalic acid, and optionally at least one additonal comonomer in a reactor at a reaction temperature below the melting temperature of the resulting polyamide polymer; drying the prepolymer; and polycondensating the dried prepolymer in an extruder, particularly a vented single screw extruder, to form the polyamide polymer.

Abstract: A process for producing poly(ester carbonates) and polyesters by reacting an aromatic or cycloaliphatic dicarboxylate salt such as sodium terephthalate with phosgene in an organic solvent in the presence of a catalytic amount of a tertiary nitrogen compound such as pyridine, optionally separating the suspended by-product inorganic salt and then interfacially reacting with a bisphenol such as bisphenol A. Excess phosgene in the diacid chloride synthesis can be carried over to the polymerization if a poly(ester carbonate) is to be produced or removed if a polyester is to be produced. Certain low levels of a tertiary nitrogen compound with a pyridine nucleus in the organic solution do not interfere with the interfacial polymerization.

Abstract: Superior bipolar membranes are prepared having high performances. The improvement is achieved by (1) using high performance component ion exchange membranes, and (2) controlling the method of joining two component membranes into a bipolar membrane. The method of preparation of high performance component ion exchange membranes is also disclosed.

Abstract: Novel single film bipolar membranes, of substantially improved efficiency and durability, i.e. having an ion selectivity above 80% in an electrolyte medium of about one mole, are prepared from pre-swollen films containing a relatively high amount, i.e. at least 15% of an insoluble cross-linked aromatic polymer. Under controlled conditions, highly dissociable cationic-exchange groups are chemically bonded to the aromatic nuclei to a desired depth of the film from one side only; subsequently, highly dissociable anion-exchange groups are chemically bonded to the unreacted aromatic nuclei on the other side of the film. The functionalized, densely structured single film ion exchange membrane undergoes negligible degradation, is blister free, and is uniquely suited for electrodialysis particularly water-splitting operations due to its low electrical resistance and low salt leakage.

Abstract: Improved novel single film bipolar membranes having an ion selectivity above 80% in an electrolyte medium of about one mole, are prepared containing a relatively high amount, i.e. at least 15% of an insoluble cross-linked aromatic polymer. Before the styrenated sheet is chemically functionalized, the film surface is specifically treated, i.e. cleaned to make it more receptive to functional groups, so that the cationic-exchange groups and anion-exchange groups can be introduced homogeneously from each side of the surface-cleaned film, and a single-film bipolar membrane of superior durability, stability, and quality control results.

Abstract: Novel single film bipolar membranes, of substantially improved efficiency and durability, i.e. having an ion selectivity above 80% in an electrolyte medium of about one mole, are prepared from pre-swollen films containing a relatively high amount, i.e. at least 15% of an insoluble cross-linked aromatic polymer. Under controlled conditions, high dissociable cationic-exchange groups are chemically bonded to the aromatic nuclei to a desired depth of the film from one side only; subsequently, highly dissociable anion-exchange groups are chemically bonded to the unreacted aromatic nuclei on the other side of the film. The functionalized, densely structured single film ion exchange membrane undergoes negligible degradation, is blister free, and is uniquely suited for electrodialysis particularly water-splitting operations due to its low electrical resistance and low salt leakage.