Abstract:
The present invention generally relates to the use of certain ruthenium and osmium complexes that are substantially inactive at a first temperature (preferably about room temperature) but becomes progressively more active at a higher second temperature. This difference in reactivities allows the reaction mixture to be formed and manipulated at the first temperature until polymerization is desired. When appropriate, the reaction mixture is heated to a suitable temperature (preferably greater than 50° C.) to activate the catalyst and to initiate polymerization. Because both the initiation and the rate of polymerization may be controlled with temperature, the inventive methods are especially suitable for ring opening metathesis polymerization (“ROMP”) reactions and for molding polymer articles that require extended pot-lives.
Abstract:
The invention relates to polymer-containing catalysts (e.g., polymer-containing organo-metal catalysts) that may be useful in various applications (e.g., polymerization of macrocyclic oligoesters). Advantages of these catalysts include the improved ability to prepare, store, and handle the catalyst in open air; higher molar volume and molecular weight; and the ability to produce a blend of reactants and a catalyst (e.g., a macrocyclic oligoester and a polymerization catalyst) for subsequent one-step reaction (e.g., polymerization of macrocyclic oligoesters).
Abstract:
A subject-matter of the present invention is a process for the preparation of a latex by radical aqueous emulsion polymerization in the presence of at least one ethylenically unsaturated monomer, of at least one radical polymerization initiator and of at least one surface-active block copolymer comprising at least one hydrophilic block and at least one hydrophobic block which is prepared by a “living” or “controlled” preparation process, the said copolymer exhibiting a number-average molecular mass of between 2 000 and 20 000, preferably between 4 000 and 16 000, a glass transition temperature of the hydrophobic block of less than 30° C., preferably of less than 25° C., and greater than −100° C., and a surface tension of less than 60 millinewtons per metre (mN/m), preferably of less than 50 mN/m, measured at a concentration in demineralized water of less than or equal to 10−4 mol/l at 20° C. and under one atmosphere, and the transfer agent having been rendered inert with respect to the said radical polymerization. The latices obtained can be used in particular in paints, adhesives and building materials.
Abstract:
A process/apparatus is disclosed for continuously separating a liquid medium comprising diluent and unreacted monomers from a polymerization effluent comprising diluent, unreacted monomers and polymer solids, comprising a continuous discharge of the polymerization effluent from a slurry reactor through a discharge valve and transfer conduit into a first intermediate pressure flash tank with a conical bottom defined by substantially straight sides inclined at an angle to that of horizontal equal to or greater than the angle of slide of the slurry/polymer solids and an exit seal chamber of such diameter (d) and length (l) as to maintain a desired volume of concentrated polymer solids/slurry in the exit seal chamber such as to form a pressure seal while continuously discharging a plug flow of concentrated polymer solids/slurry bottom product of the first flash tank from the exit seal chamber through a seal chamber exit reducer with inclined sides defined by substantially straight sides inclined at an angle to that of horizontal equal to or greater than the angle of slide of the polymer solids which remain after removal of about 50 to 100% of the inert diluent therefrom to a second flash tank at a lower pressure.
Abstract:
The invention relates to a process for the preparation of terpolymers of ethylene and at least 2 further olefinically unsaturated compounds by polymerization in a tubular reactor fitted with at least one side branch, wherein the fresh monomer components, which are introduced into the tubular reactor via the reactor inlet (the primary stream) or via the side branch or side branches (secondary stream or secondary streams), in each of the streams contain ethylene and at most one further olefinically unsaturated compound.
Abstract:
The present invention discloses a continuous process for the production of polymerized controlled architectures materials under high solids loading conditions. The materials are made under stirred, plug-flow and temperature-controlled conditions.
Abstract:
The present invention relates to novel templates useful for generating novel compounds and to compounds produced utilizing the templates. The templates comprise quaternary amino acids that may be linked to solid supports. These templates make possible the production of novel classes of chemical compounds through a plurality of chemical reactions. The templates are advantageous for use in drug discovery regimes.
Abstract:
The present invention relates to a copolymer for use in paints, resists, and the like; a method for manufacturing the same; and a resist composition using the same. The copolymer according to the present invention is obtained by means of polymerizing at least one monomer containing an alicyclic structure and one monomer containing a lactone structure, and the distribution of the copolymer composition of said monomer containing a lactone structure in said copolymer is in the range of −10 to +10 mol % of the average copolymer composition of said monomer containing a lactone structure in said entire copolymer. In addition, the copolymer according to the present invention is obtained by means of polymerizing a monomer containing an alicyclic structure, a monomer containing a lactone structure, and another vinyl monomer comprising a higher polarity than said monomer containing an alicyclic structure, but a lower polarity than said monomer containing a lactone structure. The copolymer according to the present invention exhibits superior adhesion properties to surfaces possessing a high polarity, such as metal surfaces and the like, in addition to excellent hydrophobic and thermal resistance properties, and also displays a favorable solubility in solvents used for paints, resists, and the like.
Abstract:
The present invention provides a process for recovering a dihydroxy compound from a fluid stream that results from the preparation of a polyester by use of an adsorption system to selectively recover the dihydroxy compound.
Abstract:
A high molecular weight water soluble acrylamide based polymer having improved flocculating and dewatering properties is provided. The polymer is prepared by a process in which a small quantity of a chain branching agent is added to the polymerization reaction mixture continuously or stepwise while the monomers are polymerized. The polymer is useful in solid/liquid separations such as flocculants and coagulants in wastewater treatment applications, and as thickening agents.