Abstract: Disclosed are methods and related compositions for altering the physical and chemical properties of a substrate used in hydrocarbon exploitation, such as in downhole drilling operations. In a preferred embodiment a method involves formulating a fluid, tailored to the specific drilling conditions, that contains one or more inactivated enzymes. Preferably the enzyme is inactivated by encapsulation in a pH responsive material. After the fluid has been introduced into the well bore, one or more triggering signals, such as a change in pH, is applied to the fluid that will activate or reactivate the inactivated enzyme, preferably by causing it to be released by the encapsulation material. The reactivated enzyme is capable of selectively acting upon a substrate located downhole to bring about the desired change in the chemical or physical properties of the substrate.

Abstract: This invention relates to the encapsulation of active ingredient within polymeric material so as to protect the active ingredient from the ambient environment, for instance atmospheric moisture when the product is exposed to the air, or the liquid phase of a liquid detergent when the product is incorporated in such a detergent. A dispersion in oil of an aqueous solution of a matrix polymeric material containing enzyme or other active ingredient is subjected to distillation to provide a substantially anhydrous dispersion in oil of particles of matrix polymer containing active ingredient, and during or after the distillation the polymer solution is converted into a solid polymer. In the invention, we use a matrix polymer that is so hydrophobic that it partitions preferentially into the oil rather than into the aqueous solution of encapsulating polymer.

Abstract: A particulate composition comprises particles having a substantially anhydrous core comprising an active ingredient. Generally the core comprises a matrix polymer with the active ingredient distributed throughout this. Generally there is an outer protection shell of polymer, generally formed by coacervation. The invention is a value for the production of powders, dispersions in non-aqueous liquids (for instance when the active ingredient is a detergent enzyme) and dispersions in water (for instance when the active ingredient is an agrochemical.

Abstract: A liquid composition is disclosed which comprises a substantially stable dispersion in a liquid phase of particles comprising a detergent enzyme and a protective polymeric material that is impermeable to liquid detergent concentrates but releases the enzyme when agitated in aqueous wash liquor and comprises an outer polymeric shell and/or a polymeric matrix through which the enzyme is distributed.

Abstract: Water soluble polymerizable acrylic prepolymers can be formed from ethylenically unsaturated monomers that include monomers that provide a pendant group that is a blocked, saturated, ethylenic group, followed by unblocking the pendant saturated ethylenic group to leave a pendant ethylenically unsaturated group. These prepolymers can be copolymerized through these unsaturated groups, for instance after impregnation into a permeable substrate as in chemical grouting or shut off processes, to form cross linked solid polymers. The polymerizable monomers that are ethylenically unsaturated but which also include the blocked ethylenic group are also novel.

Abstract: Enzymes and other biologically produced materials are recovered from the fermentation broth or other liquor in which they are provided initially and simultaneously distributed throughout particles of a polymeric matrix by dissolving the polymer in the liquor, dispersing the resultant polymer solution in a non-aqueous liquor in the presence of a stabiliser, and azeotroping the dispersion to produce either dry beads or a dispersion of small particles in the non-aqueous liquid.

Abstract: When drying an aqueous polysaccharide solution, the viscosification properties are maintained, and often improved, by including a low molecular weight electrolyte in the solution before the drying is completed, and generally before the solution is heated above 50.degree. C.

Abstract: Powdered polysaccharide may be made by spray drying an emulsion in a non-aqueous liquid of an aqueous solution of the polysaccharide. Spray dried polysaccharides are novel materials. At least 90% by weight of the particles may be within a size range of not more than 100 microns. The particles may have an average size between 50 and 250 microns or between 10 and 50 microns, and the finer particles can be redispersed into oil.

Abstract: A process for producing novel water-soluble compounds of the formula (HO).sub.m --A--(OCH.sub.2 NR.sup.1 COR).sub.p comprises forming a dispersion of an aqueous solution of a substrate A(OH).sub.n which is an alcohol or, preferably, a carbohydrate and a derivatising reagent HOCH.sub.2 NR.sup.1 COR.sup.2 in a water immiscible liquid and azeotroping the dispersion to remove water and thereby to drive the condensation reaction. The process can achieve high degrees of substitution and is of particular use in the production of water-soluble unsaturated polymersable products, preferably methylol acrylamide derivatives, in a process in which the aqueous dispersed phase contains a water-soluble polymerisation inhibitor. The unsaturated products may be used as cross-linking monomers in many aqueous polymerisation reactions, for instance an aqueous composition containing them with a water-soluble photo-initiator system including a dye are used as curing inks.

Abstract: A particulate substantially homogeneous polymeric product is made by dispersing ungelatinised polysaccharide in aqueous monomer containing polymerization initiator, initiating polymerization and thereby inducing exothermic polymerization, utilizing the exotherm to provide part at least of the heat necessary to gelatinise the polysaccharide and thereby producing a comminutable gel comprising polymerized monomer and gelatinised polysaccharide, comminuting the gel and drying the comminuted gel. The product generally comprises a blend of water soluble synthetic polymer, gelatinised polysaccharide having a low degree of graft polymerization and optionally gelatinised polysaccharide. Products comprising these components are particularly suitable for use as wallpaper adhesives.

Abstract: Indican, a polysaccharide comprising (1.fwdarw.3) glucose, (1.fwdarw.4) mannose, (1.fwdarw.4) rhamnose and (1.fwdarw.3 or 4) -0-(1-carboxyethyl)rhamnose units in a molar ratio of about 2:1:1-2:1 respectively; containing 12-15% by weight acetyl units [.alpha.].sub.D.sup.20 about -61.degree.; having principle absorption bands in the infra red band at 3390, 1735, 1615, 1375, 1250 and 1050 cm.sup.-1 ; a solubility of at least 1% by weight in methanol and in ethylene glycol, and an inherent viscosity of about 33.5 dl/g. has useful thixotropic properties and provides a method of modifying the viscosity of a liquid by incorporating indican therein. The liquid may be aqueous or organic solvent-based. Thickened and stabilised products are also provided.

Abstract: Indican, a polysaccharide comprising (1.fwdarw.3) glucose, (1.fwdarw.4) mannose, (1.fwdarw.4) rhamnose and (1.fwdarw.3 or 4) -0-(1-carboxyethyl)-rhamnose units in a molar ratio of about 2:1:1-2:1 respectively; containing 12-15% by weight acetyl units; [.alpha.]D.sup.20 about -61.degree.; having principle absorption bands in the infra red band at 3390, 1735, 1615, 1375, 1250 and 1050 cm.sup.-1 ; a solubility of at least 1% by weight in methanol and in ethylene glycol, and an inherent viscosity of about 33.5 dl/g. has useful thixotropic properties and provides a method of modifying the viscosity of a liquid by incorporating indican therein. The liquid may be aqueous or organic solvent-based. Thickened and stabilized products and a method of preparing indican by culture of an indican-producing microorganism are also provided.