摘要:
The invention relates to segmented N-alkyl polyurethane amides having an average molecular weight of 5,000 to 250,000, to a process for their production and to their use for the production of materials which may be used in the medical field.
摘要:
The present invention is directed to pure polyurethanes which are biocompatible. These pure polyurethanes comprise the reaction product of:a) a pre-adduct containing NCO groups and comprising the reaction product ofi) a diisocyanate selected from the group consisting of aliphatic diisocyanates, cycloaliphatic diisocyanates, and mixtures thereof, withii) a macrodiol having a molecular weight of from 500 to 10,000 wherein said components i) and ii) reacted at temperatures of from 90.degree.-150.degree. C.; withb) a chain extender having a molecular weight of from 62 to 400 and being selected from the group consisting of aliphatic diols, cycloaliphatic diols, and mixtures thereof, and optionally,c) additional diisocyanate selected from the group consisting of aliphatic diisocyanates, cycloaliphatic diisocyanates, and mixtures thereof,wherein said component c), when added, is added either simultaneously with component b) or separately from component b), the quantities of components a)i), a)ii), and c) being such that the molar ratio of diisocyanate to macrodiol is from 1.5:1 to 22:1, and the reaction of components a) and b) and optionally component c) is conducted at temperatures of from 90.degree. to 230.degree. C., with the proviso that the reaction conditions are maintained until said polyurethane has a melt viscosity of at least 2500 mPa.s at 120.degree. C.
摘要:
The present invention relates to shaped articles which contain active compounds and are characterized in that they comprise, as carriers, thermoplastic elastomers based on polyether block amides, as well as customary additives if appropriate, and to processes for their production and to their use for control of pests in animals.
摘要:
The invention relates to thermoplastic polyurethanes modified with segmented siloxane block copolymers which are based on relatively high molecular weight dihydroxy compounds, diisocyanates, and difunctional chain extenders. The application also relates to their use in the medical field, and particularly as a catheter material.
摘要:
The invention relates to blends of polyether copolycarbonates and other thermoplastics, to their production and to their use for the production of membranes, more particularly for dialysis.
摘要:
Disclosed is a diagnostic test device which comprises a fluid permeable structural support member having on one side thereof a layer of a macroporous membrane comprising polyethyleneimine impregnated with iodate ion and on the other side of the support member having a layer of a microporous membrane having dispersed therein a chromogenic indicator capable of providing a colored response upon being oxidized.The intensity of the colored response is less subject to ascorbate interference due to the activity of the iodate ion.
摘要:
A process for the preparation of a polyurethane-urea elastomer having a mole ratio of NCO groups to all active hydrogen atoms in the range of 0.9 to 1.2 is disclosed. The process comprise reacting (A), (B) and (C.2) for form an NCO-containing prepolymer and then reacting said prepolymer with (C.1) and (D). Accordingly (A) is 5-isocyanato-1-(isocyanatomethyl)-1,1,3-trimethylcyclohexane or bis-(4-isocyanatocyclohexyl)-methane,(B) is polytetrahydrofuran or hexanediol polycarbonate and (C.2) is a chain extender. (C.1) is 5-amino-3-amino-methyl-1,3,3-trimethylcyclohexane or bis-(4-aminocyclohexyl)-methane and (D) is a molecular weight regulator. The elastomer thus produced is particularly suitable for the preparation of moldings, films, flexible tubing (for medical purposes) and catheters.
摘要:
Asymmetric semipermeable membranes which consist of aromatic polycondensates having recurring units of the formula(--O--Z--O--Y--).sub.n (I)in whichY is the divalent radical of an aromatic sulphone or of an aromatic ketone and--O--Z--O--is a divalent diphenolate radical which consists to the extent of 0.1-100 mol % of all the diphenolate radicals of those of the formula ##STR1## with the meaning given in the description, are suitable for haemodialysis, haemodiafiltration, haemofiltration, ultrafiltration, microfiltration and reverse osmosis.
摘要:
The present invention provides polycarbonates with aliphatic ketocarboxyl end groups, optionally mixed with known aromatic polycarbonates, and a process for their preparation, the chain terminators used being those of formula (I): ##STR1## The present invention also provides mixtures of the polycarbonates or polycarbonate mixtures with reactionless polyisobutylenes.