Abstract: A mixture of a short chain linear phosphazene having the formula:X.sub.3-p (HO).sub.p P(NPX2).sub.m NP(O)X.sub.2,where X is a halogen selected from the group consisting of F, Cl, Br, and I, and m is an integer ranging from 0 to 6 and p is 0 or 1; anda linear sifoxane having a viscosity ranging from 1 to 5,000 centistokes is a catalyst for the polymerization, condensation, or redistribution of siloxanes; the process of making the catalyst and the process of using the catalyst.

Abstract: A batch or continuous process for the production of low molecular weight hydrogen siloxanes catalyzed by soluble phosphonitrilic halides or solid acid catalysts such as acid washed clays, zeolites and ion exchange resins.

Abstract: Use of a certain class of acid washed clays enables a fixed bed process for the production of very low viscosity low silanol content silicone fluids to be produced in a fixed bed single reactor process.

Abstract: Linear triorganosiloxy-terminated polydiorganosiloxanes having a silanol content of less than about 200 ppm are prepared by condensing linear higher molecular weight polydiorganopolysiloxanediols having one Si-bonded hydroxyl group in each terminal unit and a silanol content of preferably greater than about 1000, in two separate stages, one using a fixed bed of a solid form of a conventional equilibration catalyst, and the other using a condensation/disproportionation catalyst, e.g., a phosphonitrilic halide or an oligomer thereof or a reaction product thereof with water, an alcohol, an acid, or a siloxane or silane, until the polydiorganosiloxane has reached the desired low content of silanol groups, e.g., below 200 ppm, by weight. The two stages can be carried out in either order, and a conventional monofunctional chain terminating agent can be present in either or both stages. The process preferably does not increase the cyclic byproduct content.

Abstract: A process disclosed for the production of organosiloxanes which is based on the use of a judiciously selected catalyst, e.g., a phosphorus-nitrogen homopolymeric or oligomeric compound, a derivative thereof, a complex thereof, sulfuric acid, a fluorinated alkane sulfonic acid, a kaolin clay, or a mixture of any of the foregoing, to disproportionate or to condense and disproportionate a mixture of two different organosiloxanes which have different molecular weights, without, at the same time, increasing the cyclics content of the mixture.

Abstract: Linear triorganosiloxy-terminated polydiorganosiloxanes having a silanol content of less than about 200 ppm are prepared by condensing linear higher molecular weight polydiorganopolysiloxanediols having one Si-bonded hydroxyl group in each terminal unit and a silanol content of preferably greater than about 1000, in two separate stages, one using a fixed bed of a solid form of a conventional equilibration catalyst, and the other using a condensation/disproportionation catalyst, e.g., a phosphonitrilic halide or an oligomer thereof or a reaction product thereof with water, an alcohol, an acid, or a siloxane or silane, until the polydiorganosiloxane has reached the desired low content of silanol groups, e.g., below 200 ppm, by weight. The two stages can be carried out in either order, and a conventional monofunctional chain terminating agent can be present in either or both stages. The process preferably does not increase the cyclic byproduct content.

Abstract: Polyarylene ether-organopolysiloxane copolymers are provided having amine, or ester connecting linkages between blocks resulting from the melt extrusion of epoxy, carboxy or amine functionalized polyarylene ether with epoxy, carboxy or amine functionalized organopolysiloxane.

Abstract: Block copolymers of polyarylene sulfide with either polyimide, or polydiorgano siloxane are provided. Various methods for making such block copolymers are shown which are useful as compatabilizers for blends of polyarylene sulfide with polyimides and polydiorgano siloxanes.

Abstract: A method is provided for enhancing the crystallization rate of certain polyetherimide to provide an improved molding mehod for making solvent resistant shaped thermoplastics. Polyetherimide blends containing crystallization rate enhancing agents such as bisimides or imide oligomers also are provided.

Abstract: 4-Hydroxy-3-phenylbenzoic acid is prepared by carbonation of a 2-phenylphenol alkali metal salt in the presence of a liquid N,N-dialkylcarboxamide such as dimethylformamide. Carbonation may be effected at atmospheric pressure or at superatmospheric pressures.

Abstract: A method is provided for making organobis(thioether)s which include bis(thioetherimide)s and bis(thioetheranhydride)s. There is also provided alkylene bis(thioetherimide)s and the corresponding dianhydrides thereof which can be used to make crystalline polyimides.

Abstract: Block copolymers of polyarylene sulfide with either polyimide, or polydiorgano siloxane are provided. Various methods for making such block copolymers are shown which are useful as compatabilizers for blends of polyarylene sulfide with polyimides and polydiorgano siloaxanes.

Abstract: Secondary amine-terminated aromatic oligomers are prepared by conventional reactions for the formation of such polymers as polyimides, polyethersulfones and polyetherketones, using such compounds as methylamino or phenylamino anilines or phenols as endcapping agents. The secondary amine-terminated oligomers may be reacted with cyclic polycarbonate oligomers to prepare copolyurethanecarbonates which are useful as engineering thermoplastics.

Abstract: Copolycarbonates are prepared by ring-opening cyclic polycarbonate oligomers with various nucleophilic polymers. The latter include "living" anionic vinyl polymers; polymers such as polyphenylene ethers or hydroxyaryl-terminated polyimides which contain deprotonated hydroxy or carboxy groups; polymers containing neutral nucleophilic moieties, such as secondary amine-terminated polyimides, polyethersulfones and polyetherketones; and anionic polymers of ring-opened compounds such as cyclic polysiloxanes, lactams and lactones.

Abstract: Crystalline polyimides having low glass transition temperatures and high solvent resistance are obtained by reacting diamino-oligo-phenylene sulfides with aromatic tetracarboxylic acids or their anhydride derivatives. The diamino-oligo-phenylene sulfides can be of varying length and can be reacted with the dianhydride by conventional processes.

Abstract: Secondary amine-terminated aromatic oligomers are prepared by conventional reactions for the formation of such polymers as polyimides, polyethersulfones and polyetherketones, using such compounds as methylamino or phenylamino anilines or phenols as endcapping agents. The secondary amine-terminated oligomers may be reacted with cyclic polycarbonate oligomers to prepare copolyurethanecarbonates which are useful as engineering thermoplastics.

Abstract: Crystalline polyetherimides having equilibrium melting points below 400.degree. C. are obtained by the reaction of various p-linked polycyclic tetracarboxylic acids or their functional derivatives with p-linked polycyclic diamines. The structural units in said crystalline polyetherimides contain at least 7 aromatic rings.