Abstract: The invention relates to pyran derivatives of formula I and processes and intermediates for their preparation and derivatisation, and the use thereof in liquid-crystalline media.

Abstract: The invention relates to pyran derivatives of the formula I and to a process and intermediates for their preparation and derivatisation, and to the use thereof in liquid-crystalline media.

Abstract: A tetrahydropyran derivative comprising at least three cyclic rings and one aromatic endgroup of the formula A a process for preparing said tetrahydropyran derivatives, and the use of said tetrahydropyran derivatives as a component in a liquid crystal composition.

Abstract: Graft polymers are disclosed. These are obtainable by polymerization of a mixture containing A) from 40 to 99 wt. % vinyl monomers and B) from 1 to 60 wt. % of a double-bond-containing polyalkylene oxide rubber having a glass transition temperature below −50° C. and a number-average molecular weight of from 25,000 to 10,000,000. The inventive graft polymers are characterized by their very good low-temperature strength and weathering resistance.

Abstract: Aldehydes containing a difluorooxymethylene bridge, of the general formula I

Abstract: A process for the preparation of any of well-defined homopolymers, random and block copolymers is disclosed. The process that entails forming a mixture of monomers, a hindered secondary amine and an oxidizing agent is characterized in the absence of any additional free-radical initiator.

Abstract: A process for the preparation of (co)oligomers or (co)polymers is disclosed.

Abstract: A process for the production of polymers by means of pseudo-living free-radical polymerization is disclosed. The process entails (i) reacting a polymerizable vinyl monomer with nitrogen monoxide and at least one initiator to prepare a free-radical intermediate product, and (ii) polymerizing the intermediate product optionally together with one or more additional monomers and/or with a free-radical initiator.

Abstract: Segmented polyurethane/ureas useful in the production of spandex are produced by chain extending an isocyanate-terminated prepolymer with a diamine chain extender that includes: (1) from about 7 to 25 equivalent percent of an asymmetric aliphatic and/or cycloaliphatic diamine and (2) a linear diamine such as ethylene diamine in the presence of a solvent. The isocyanate-terminated prepolymer is produced by reacting a stoichiometric excess of an isocyanate with an isocyanate-reactive component that includes: (1) from about 10 to about 70 equivalent percent of a polyoxypropylene diol having a molecular weight in excess of 1500 Da and an average unsaturation level no greater than about 0.03 meq/g and (2) from about 30 to about 90 equivalent percent of a polytetramethylene ether glycol having a molecular weight of at least 600 Da.

Abstract: A one-pot process for the preparation of functional alkoxyamines of the general formula (I), is disclosed. The process entails (1) reacting an oxidizing agent with a sterically hindered secondary amine to produce an aqueous phase and a nitroxyl radical (2) removing the aqueous phase and adding to the nitroxyl radical one or more vinyl monomer(s) conforming to a formula and a system which produces free radicals. Also disclosed is a process of polymerizing monomers using the functional alkoxyamine.

Abstract: A one-pot process for the preparation of alkoxyamines conforming to formulae (I) or (II), preferably (I) 1

Abstract: A one-pot process for the preparation of functional alkoxyamines of the general formula (I), 1

Abstract: Segmented polyurethane/ureas useful for the production of spandex, particularly spandex fibers, are made from isocyanate-terminated prepolymers formed by reacting excess isocyanate with an isocyanate-reactive component satisfying specified compositional requirements in the presence of a catalyst which promotes linear polymerization but does not cause degradation of the polymer. Suitable catalysts include metal salts of organic fatty acids and/or of naphthenic acid. The isocyanate-reactive component includes at least 10 equivalent percent of a polyoxypropylene diol having a number average molecular weight of at least about 1500 Da and an average unsaturation level less than or equal to 0.03 meq/g and up to 90 equivalent percent of a polytetramethylene glycol having a number average molecular weight of at least 200 Da.

Abstract: Segmented polyurethane/ureas useful in the production of spandex are produced by chain extending an isocyanate-terminated prepolymer with a diamine chain extender that includes: (1) from about 7 to 25 equivalent percent of an asymmetric aliphatic and/or cycloaliphatic diamine and (2) a linear diamine such as ethylene diamine in the presence of a solvent. The isocyanate-terminated prepolymer is produced by reacting a stoichiometric excess of an isocyanate with an isocyanate-reactive component that includes: (1) from about 10 to about 70 equivalent percent of a polyoxypropylene diol having a molecular weight in excess of 1500 Da and an average unsaturation level no greater than about 0.03 meq/g and (2) from about 30 to about 90 equivalent percent of a polytetramethylene ether glycol having a molecular weight of at least 600 Da.

Abstract: Described is a process for producing segmented polyurethanes having improved processing characteristics in the melt state and an efficient spinning process based thereon to form highly elastic, fine linear density elastane yarn and filament having improved mechanical and thermal properties by using hydroxyalkyl-terminated polysiloxanes in combination with specific crosslinking-capable polyisocyanates in the reaction of long-chain high molecular weight polyhydroxy compounds with organic diisocyanates and low molecular weight diols and also optionally further auxiliary and additive substances in the melt.

Abstract: A process for producing a superabsorbent polymer is described. The process that entails a continuous hydrolysis of an aqueous emulsion of crosslinked or uncrosslinked polyacrylonitrile in the form of fine particles is carried out in a cascade of stirred tanks. The reaction with alkali-hydroxide solution an aqueous-alcoholic medium at 60 to 100° C. yields polymers that are suitable for the preparation of hygiene products, water-storing materials in agriculture, and sheathing of electrical cables.

Abstract: The instant invention relates to liquid crystal media comprising a strongly dielectrically positive component A, preferably comprising isothiocyanate compounds, most preferably compounds of formula I, as given in the text, and a further dielectrically positive component B, preferably comprising terminally polar substituted bi- or terphenyl compounds, most preferably comprising compounds of formula II, as given in the text, further to novel isothiocyanato compounds as well as to liquid crystal displays comprising these media, in particular to PDLC display and most particular to holographic PDLC displays. The instant invention further relates to compounds of formula I wherein the parameters are as as specified in the text.

Abstract: The invention relates to a method for agglomerating finely divided rubber latices by adding an aqueous solution of a water-soluble amphiphilic copolymer that consists of at least one hydrophilic portion and at least one hydrophobic portion. The inventive method is further characterized in that the molar weight HB of the largest hydrophobic portion and the molar weight HL of the largest hydrophobic portion of the amphiphilic copolymer exceed the following minimum values: HB>500 g/mol and HL>2000 g/mol.

Abstract: The invention relates to novel branched polyether carbonates, which are produced with the alpha-halocarboxylic esters of polyols as branching agent, whereby the branching agent is incorporated in the polycarbonate by means of ether bridges.

Abstract: A process for the production of polymers by means of pseudo-living free-radical polymerization is disclosed. The process entails (i) reacting a polymerizable vinyl monomer with nitrogen monoxide and at least one initiator to prepare a free-radical intermediate product, and (ii) polymerizing the intermediate product optionally together with one or more additional monomers and/or with a free-radical initiator.