Abstract: An end of life indicator for use in a toilet cistern with an ambient solution containing an active disinfectant component. The end of life indicator comprises a core of water soluble dyestuff surrounded by a polymer resistant to bleaching by said disinfectant solution. Upon the depletion of the active disinfectant component surrounding the end of life indicator, the alkalinity of the solution increases to a predetermined level whereupon hydrolysis of the polymer coating continues until water penetrates or dissolves the coating sufficiently to come into contact with the water soluble dye.

Abstract: Plugging perforations in casing in a wellbore penetrating a subterranean formation using degradale ball sealers. The ball sealer used is composed of a polyester polymer which is substantially insoluble in the wellbore fluid. The polymer degrades in the presence of water at an elevated temperature to form small molecules which are soluble in a fluid in the subterranean formation. After the polymer degrades, the flow through the perforation returns to substantially its initial value.

Abstract: The invention provides a novel efficient method for the preparation of a polyarylene sulfide or, typically, polyphenylene sulfide by the reaction of an alkali metal sulfide, e.g. Na.sub.2 S, and a polyhalogenated aromatic compound, e.g. 1,4-dichlorobenzene. The improvement in the inventive method comprises performing the reaction in a heterogeneous reaction mixture comprising water and a polyethyleneglycol having a relatively high molecular weight, namely an average molecular weight of from 2,000 to 20,000, and not freely miscible with water. The product polymer is outstandingly free from salt impurities, e.g. sodium chloride, as a byproduct of the reaction. When a low molecular polyethyleneglycol is added to the reaction mixture in combination with the above mentioned high molecular polyethyleneglycol, a remarkable catalytic effect is obtained to accelerate the reaction and increase the yield of the desired polymer product.

Abstract: The present invention is a novel class of block copolymers and a process of making the same. An alkylene oxide is reacted with CO.sub.2 in an organic solvent in the presence of an organometallic catalyst to form a polyalkylene carbonate. A second alkylene oxide is subsequently added without the addition of catalyst. The resulting product is a block copolymer comprising distinct, covalently linked, alkylene carbonate blocks.

Abstract: Metal castings having reduced residual carbon ash and surface flaws are produced by an evaporative pattern casting process, in which an organic foam pattern is vaporized upon contact with a molten metal leaving a metal replica of the pattern. The organic foam used in this process comprises a polymer formed by polymerizing CO.sub.2 with one or more oxirane compounds.

Abstract: The present invention relates generally to the composition and method for reducing the permeability of subterranean formations penetrated by a wellbore. The composition of the present invention comprises a wellbore fluid having dispersed therein a fluid loss control agent comprising a polyester polymer which is substantially insoluble in the wellbore fluid. The polymer degrades in the presence of water at an elevated temperature to form small molecules which are soluble in a fluid in the subterranean formation. The method of the present invention comprises reducing the permeability of subterranean formations penetrated by a wellbore by placing the composition of the present invention down the wellbore.

Abstract: The present invention relates generally to the composition and method for reducing the permeability of subterranean formations penetrated by a wellbore. The composition of the present invention comprises a wellbore fluid having dispersed therein a fluid loss control agent comprising a polyester polymer which is substantially insoluble in the wellbore fluid. The polymer degrades in the presence of water at an elevated temperature to form small molecules which are soluble in a fluid in the subterranean formation. The method of the present invention comprises reducing the permeability of subterranean formations penetrated by a wellbore by placing the composition of the present invention down the wellbore.

Abstract: A block copolymer dispersion stabilizer for use in the aqueous dispersion polymerization of an ethylenically unsaturated monomer comprises at least two blocks linked by chemical valences. At least one of the blocks is hydrophilic (water soluble) and at least another of said blocks is hydrophobic (water insoluble). The hydrophobic block can contain a plurality of similar or dissimilar pendent groups having chemically reactive functionality. Examples of such groups are epoxy groups and ethylenically unsaturated bonds.

Abstract: A process for the non-aqueous dispersion polymerization of a conjugated diolefin monomer, for instance, butadiene or isoprene, in a liquid hydrocarbon dispersion medium, for instance, n-butane or n-pentane with a Ziegler Natta catalyst, for instance, triisobutylaluminum/titanium tetrachloride while said conjugated diolefin is in the presence of a block copolymer dispersion stabilizer. The block copolymer dispersion stabilizer is a copolymer which contains at least two blocks of polymer linked by chemical valences, at least one block (A block) is soluble in liquid organic dispersion medium and at least another block (B block) is insoluble in the dispersion medium and the stabilizer acts to disperse polymers of conjugated diolefins which are formed in the stabilizer's presence. The A block is exemplified by polyisoprene, poly(t-butyl styrene) and poly(vinyl toluene). The B block is exemplified by polystyrene, poly(.alpha.

Abstract: A free-flowing, homogeneous, polymer-coated pigment, particulate powder coating composition is obtained in preparing a coating composition involving catalytic polymerization of at least one ethylenically unsaturated monomer in a nonaqueous aliphatic hydrocarbon solvent for said monomer and in the presence of a dispersion stabilizer having a polymeric segment solvated by said solvent and another segment relatively non-solvated by the solvent and associated with polymer particles which are formed upon said polymerization of said monomer and which are insoluble in said solvent for providing a nonaqueous dispersion of said polymer particles, through a sequence of steps including:I. preparing said dispersion stabilizer in a solution containing a coalescing solvent which is an active solvent for said polymer particles;Ii. admixing a portion of the product of (i) with said pigment to form a pigment dispersion;Iii. drying another portion of the product of (i);Iv.

Abstract: Copolymers which can be fabricated into films, fibers and structural shapes are prepared by copolymerizing an optically active lactide, i.e., L-(-)-lactide, and epsilon caprolactone in the presence of a tin ester of a carboxylic acid. A copolymer prepared from 75 parts by weight of L-(-)-lactide and 25 parts by weight of epsilon caprolactone is a thermoplastic elastomer. A copolymer prepared from 90 parts by weight of L-(-)-lactide and 10 parts by weight of epsilon caprolactone is a rigid, clear, thermoplastic solid.

Abstract: Copolymers which can be fabricated into films, fibers and structural shapes are prepared by copolymerizing an optically inactive lactide, i.e., D,L-lactide, and epsilon caprolactone in the presence of a tin ester of a carboxylic acid. A copolymer prepared from 85 parts by weight of D,L-lactide and 15 parts by weight of epsilon caprolactone is a thermoplastic elastomer. A copolymer prepared from 90 parts by weight of D,L-lactide and 10 parts by weight of epsilon caprolactone is a rigid, clear, thermoplastic solid.