摘要:
The present invention relates to aqueous emulsions of polymers which contain 80 to 100 weight % of acrylonitrile polymerized within them, to a method for their preparation, and to their use as raw materials for acrylic and modacrylic fibres and as dyeing additives for adjusting the dyestuff affinity of cationic dyestuffs for conventional acrylic and modacrylic polymers and fibre materials produced from them.
摘要:
Super-absorbent polymer in the form of pre-formed spherical particles obtainable by alkaline hydrolysis of aqueous emulsions of crosslinked and/or un-crosslinked homopolymers and/or copolymers of acrylonitrile in water/alcohol mixtures and the use of the polymer in hygiene products, as a water-storing material in agriculture and for the sheathing of electrical cables.
摘要:
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.
摘要:
A process for modifying superabsorbent polymers is disclosed. The surface of a polymer containing hydrolyzed polyacrylonitrile in the form of particulates, is modified by crosslinking in a water/alcohol reaction mixture and in the presence of silica. The resulting product features improved absorbency under load and lesser degree of gel blocking.
摘要:
A process for the production of super-absorbent polymers with a swelling capacity in water-containing liquids of up to 1,000 g/g in which aqueous emulsions of particularly high molecular weight polymers of acrylonitrile are partly hydrolyzed by reaction with aqueous solutions of alkali metal and/or alkaline earth metal hydroxides, the polymers are precipitated in powder form by addition of water-miscible organic solvents, separated off, dried and then optionally heated for a short time. The super-absorbent polymers are used as water-storing materials, for example in sanitary articles, in agriculture or in the sheathing of electrical cables.
摘要:
A process for the production of super-absorbent polymers with a swelling capacity in water-containing liquids of up to 1,000 g/g in which aqueous emulsions of particularly high molecular weight polymers of acrylonitrile are partly hydrolyzed by reaction with aqueous solutions of alkali metal and/or alkaline earth metal hydroxides, the polymers are precipitated in powder form by addition of water-miscible organic solvents, separated off, dried and then optionally heated for a short time. The super-absorbent polymers are used as water-storing materials, for example in sanitary articles, in agriculture or in the sheathing of electrical cables.
摘要:
The present invention relates to a process for preparing polyisocyanates containing isocyanurate groups by trimerizing a portion of the isocyanate groups of an organic polyisocyanate component containing a) one or more diisocyanates corresponding to formula (1) ##STR1## wherein R represents a saturated, straight-chain, aliphatic hydrocarbon group having 8 to 15 carbon atoms and optionally b) up to 95 NCO equivalent-%, based on the total equivalents a) and b), of one or more organic polyisocyanates other than a), in the presence of trimerization catalysts and terminating the trimerization reaction at any desired degree of trimerization. The invention also relates to the polyisocyanates containing isocyanurate groups obtained by this process and to their use, optionally in excess starting polyisocyanates and optionally blocked with blocking agents for isocyanate groups, as an isocyanate component for preparing polyisocyanate addition products.
摘要:
The invention relates to new hexahydrotriazinetrione-containing high molecular weight polyarylene sulphides (PAS), preferably polyphenylene sulphides (PPS), and a process for their preparation.
摘要:
The invention relates to new, free-flowing polyamide molding compounds and blends, characterized in that they are prepared by mixing of polyamides known per se in the melt with low molecular weight, liquid-crystalline esters and/or ester amides corresponding to formula (I) and/or liquid-crystalline, oligomeric esters and/or ester amides corresponding to formula (II) and, optionally, other additives, at least one polymeric blending component being used as a further additive in the case of polyamide blends, and to the use of these liquid-crystalline (LC) additives I and/or II as flow promoters in polyamide molding compounds and blends and to a process for the production of the new polyamide molding compounds and blends. The invention also relates to the new oligomeric esters and/or ester amides corresponding to formula (II).