Abstract:
The present invention provides novel bimetallic complexes and methods of using the same in the isoselective polymerization of epoxides. The invention also provides methods of kinetic resolution of epoxides. The invention further provides polyethers with high enantiomeric excess that are useful in applications ranging from consumer goods to materials.
Abstract:
Die Erfindung betrifft ein Verfahren zur Herstellung von Homopolymeren aus Oxiranen, oder von Copolymeren aus Oxiranen und Comonomeren, durch anionische Polymerisation, dadurch gekennzeichnet, dass man in Gegenwart einer quartären Ammonium und/oder Phosphoniumverbindung und eines einkernigen Aluminiumorganyls polymerisiert.
Abstract:
Polyoxyalkylenepolyols or monools (I) represented by general formula (1) which are characterized in that at least 40 % of the hydroxyl-containing -AO-H groups located at the end are primary hydroxyl-containing groups represented by general formula (2); and a process for producing a ring-opened polymer by ring-opening polymerizing an active hydrogen-containing compound and a cyclic compound with the use of tris(pentafluorophenyl)borane, tris(pentafluoro-phenyl)aluminum, etc., as a catalyst.
Abstract:
Disclosed are novel polyether compounds obtained by the reaction or polymerization of 3,4-epoxy-1-butene in the presence of an onium iodide compound such as an ammonium or phosphonium iodide, an organotin compound such as a trihydrocarbyltin iodide, and a nucleophilic initiator compound. The polyether compounds comprise n units of residue (1) and m units of residue (2), wherein the total value of n + m is 2 to 70, m/(n + m) is greater than 0.75 and up to 0.98, and residues (1) and (2) have the structures (1) and (2).
Abstract:
Reactive and hydrolytically-degradable poly(alkylene oxide) derivatives and methods for their synthesis are described herein. These polymers differ from poly(alkylene oxide) by the controlled incorporation of degradable repeat units together with alkylene oxide units. The degradable polymers contain vinyl ether degradable units (e.g., methylene ethylene oxide) incorporated into a polyalkylene backbone (e.g., ethylene oxide, propylene oxide, butylene oxide, other alkylene oxides, glycidol, methyl glycidyl ether, ethyl glycidyl ether, allyl glycidyl ether, or other repeat units derived among the glycidyl ethers). The alkylene oxides and glycidyl ethers may be racemic mixtures, enantiomerically enriched, or enantiomerically pure. The degradable polymers disclosed herein can be used in applications where hydrolytic degradability under physiological, or physiological-like conditions is desirable, such as pharmaceutical and cosmetic formulations and degradable devices.
Abstract:
Polyoxymethylene polymer compositions are disclosed that contain an impact modifier. In accordance with the present disclosure, the impact modifier is attached to the polyoxymethylene polymer and comprises a thermoplastic elastomer containing carbonate groups, such as polycarbonate groups. In one embodiment, a coupling agent bonds the impact modifier to the polyoxymethylene polymer. Incorporation of an impact modifier containing carbonate groups has been found to produce articles having good impact resistance properties while also preserving the permeability of the material. The polymer composition is well suited to producing containment devices, especially fuel tanks.