A method of forming thermoplastic polyurethane (TPU) into an optical lens. Suitable TPUs contain urethane (—NHCOO—) repeating units that are present in at least 23% by weight. This range of urethane weights is an indicator of a flexural modulus above 1,400 MPa. The TPUs have refractive...
of EP0787751 Aqueous dispersions (AD) containing a polyurethane (PU) derived from (a) 4-30C di-isocyanates, (b) diol(s), of which (b1) 10-100 mole% have a mol. wt. of 500-5000 and are derived from (b1.1) (4-30C alkyl and/or alkenyl)-succinic acid, (b1.2) 0-60 mole% ...
Then, the obtained cyclohexane-based polyether polyol (CPOL) further reacted with 4,4 '-diphenylmethane diisocyanate to form reactive polyurethane adhesive (RPUA). The thermal properties and mechanical strength of the RPUA were characterized by differential scanning calorimetry, dynamic mechanical ...
Then, the obtained cyclohexane-based polyether polyol (CPOL) further reacted with 4,4 '-diphenylmethane diisocyanate to form reactive polyurethane adhesive (RPUA). The thermal properties and mechanical strength of the RPUA were characterized by differential scanning calorimetry, dynamic mechanical ...
A repeating block, polyphase, thermoplastic polyurethane is obtd. by reacting an isocyanate-terminated prepolymer (I); opt. additional diisocyanate (II); an amt. of a chain-extender (III) sufficient to give isocyanate index 1.025-1.035; and a catalyst (IV). (I) consists of n-branched, ...
A method of forming thermoplastic polyurethane (TPU) into an optical lens. Suitable TPUs contain urethane (—NHCOO—) repeating units that are present in at least 23% by weight. This range of urethane weights is an indicator of a flexural modulus above 1,400 MPa. The TPUs have refractive...
Aqueous dispersions (AD) containing a polyurethane (PU) derived from (a) 4-30C di-isocyanates, (b) diol(s), of which (b1) 10-100 mole% have a mol. wt. of 500-5000 and are derived from (b1.1) (4-30C alkyl and/or alkenyl)-succinic acid, (b1.2) 0-60 mole% (based on b...
NO REPEATING BLOCK OLIGOMER-CONTAINING MULTIPHASE HEAT-MOLDABLE POLYURETHANE AND ITS PRODUCTIONPolyphase, transparent, polyblock, oligomer-free, segmented urethane polymers having molecular weights of from about 100,000 to about 200,000 and being eminently suited for use in medical devices such as blood...