Abstract: Processing by melt extrusion a surface-segregatable, melt-extrudable thermoplastic composition to form a fiber or film having a differential, increasing concentration of an additive from the center of the fiber or film to the surface thereof, which differential, increasing concentration imparts to the surface of the fiber or film at least one desired characteristic which otherwise would not be present, which composition includes at least one thermoplastic polymer and at least one defined additive. During formation of the fiber or film, the additive rapidly segregates in a controllable manner toward the newly-formed surface of the fiber or film, thereby resulting in a controllable differential concentration of the polymeric material, which concentration increases with increasing distance from the center of the fiber or film to its surface.

Abstract: A method of cleaning melt-processing equipment which comprises processing in such equipment a thermoplastic composition which comprises at least one thermoplastic polyolefin and at least one siloxane-containing additive having at least two moieties, A and B, in which:(A) said additive is compatible with said polyolefin at melt extrusion temperatures but is incompatible at temperatures below melt extrusion temperatures, but each of moiety A and moiety B, if present as separate compounds, would be incompatible with said polyolefin at melt extrusion temperatures and at temperatures below melt extrusion temperatures;(B) moiety A contains at least one tetrasubstituted disiloxanylene group;(C) moiety B has at least one functional group which is a poly(oxyalkylene) moiety;(D) the molecular weight of said additive is in the range of from about 400 to about 16,000; and(E) said additive is present in said thermoplastic composition at a level of from about 3 to about 12 percent by weight, based on the weight of said the

Abstract: A composite structure having a thickness substantially less than its width such as a sheet is prepared which includes a substantially water-insoluble particulate or fibrous support having a surface energy of at least about 30 dynes per cm to which nitrogen-fixing filamentous blue-green algae heterocyst cells are attached. the support does not have a deleterious effect on the attached algae and is preferably cellulosic or a polyoletin such a polypropylene. The structure may contain a first and second layer and have a plurality of raised, three-dimensional shapes over at least a portion of at least one surface. Preparing the composite structure includes contacting the support with blue-green algae to permit the algae to attach to the support by means of heterocyst cells. The attach cells in a nitrogen deficient environment, fix nitrogen at a rate substantially greater than unattached cells, and have agricultural applications.

Abstract: A surface-segregatable, melt-extrudable thermoplastic composition suitable for processing by melt extrusion to form a fiber or film having a differential, increasing concentration of an additive from the center of the fiber or film to the surface thereof, which differential, increasing concentration imparts to the surface of the fiber or film at least one desired characteristic which otherwise would not be present, which composition includes at least one thermoplastic polymer and at least one defined additive. During formation of the fiber or film, the additive rapidly segregates in a controllable manner toward the newly-formed surface of the fiber or film, thereby resulting in a controllable differential concentration of the polymeric material, which concentration increases with increasing distance from the center of the fiber or film to its surface. The weight ratio of the polymer to the additive is in the range of from about 1 to about 1,000.

Abstract: A composite is prepared which includes a substantially water-insoluble particulate or fibrous support having a surface energy of at least about 19 dynes per cm to which nitrogen-fixing filamentous heterocystous blue-green algae are attached. The support does not have a deleterious effect on the viability of the attached algae, and is preferably polypropylene or cellulosic. Preparing the composite includes contacting the support with blue-green algae to permit the algae to attach to the support by means of heterocyst cells. The attached cells in a nitrogen-deficient environment, fix nitrogen at a rate substantially greater than unattached cells, and have agricultural applications.

Abstract: A stabilized surface-segregatable, melt-extrudable thermoplastic composition suitable for processing by melt extrusion to form a fiber or film having a differential, increasing concentration of a siloxane-containing primary additive from the center of the fiber or film to the surface thereof, which differential, increasing concentration imparts hydrophilicity to the surface of the fiber or film, which composition includes at least one thermoplastic polymer, at least one siloxane-containing primary additive, and at least one siloxane-containing stabilizing additive. During formation of the fiber or film, the primary additive rapidly segregates in a controllable manner toward the newly-formed surface of the fiber or film, thereby resulting in a controllable differential concentration of the primary additive, which concentration increases with increasing distance from the center of the fiber or film to its surface. The weight ratio of the polymer to the additive is in the range of from about 1 to about 1,000.

Abstract: A multilayer structure is prepared containing immobilized nitrogen-fixing filamentous blue-green algal heterocyst cells. The cells are attached to a first layer which is a water-insoluble support having a surface energy of about 30 to about 115 dynes per cm. Second and third layers are adjacent and contiguous with first and second surfaces, respectively, of the first layer. At least one of the second and third layers is transparent to actinic radiation. The support may be cellulosic such as wood pulp. The immobilized cells fix nitrogen at a rate which is substantially greater than cells when not immobilized. The structure is useful as a nutrient source for agricultural purposes.

Abstract: A siloxane which contains at least one benzotriazolyl/tetraalkylpiperidyl group, which siloxane can be represented by the general formula, S-Z, in which S represents a siloxane moiety and Z represents a pendant benzotriazolyl/tetraalkylpiperidyl group attached by means of a divalent connecting group to a silicon atom.The compounds are useful as additives for the preparation of surface-segregatable, melt-extrudable thermoplastic compositions. The compositions, in turn, are useful for the preparation of fibers and films by melt extrusion, which fibers and films have enhanced stability to degradation by actinic radiation.

Abstract: A nonwoven web is prepared by the method of forming a nonwoven web from a composition composed of at least one thermoplastic polymer and at least one defined siloxane-containing additive, which method involves the steps of (A) forming fibers by extruding a molten thermoplastic composition through a die; (B) drawing the fibers; (C) collecting the fibers on a moving foraminous surface as a web of entangled fibers; and (D) heating the web at a temperature of from about 27.degree. to about 95.degree. C. for a period of time sufficient to cause additional additive to move to the surfaces of the fibers. The method of the present invention is particularly useful for the preparation of nonwoven webs, the fibers of which have at least one surface characteristic which is different from the surface characteristics of the polymer component of the thermoplastsic composition.

Abstract: A shaped polyolefin structure, such as a polyolefin fiber or a nonwoven web containing polyolefin fibers, is rendered hydrophilic by contacting the structure with a gaseous mixture of chlorine, sulfur dioxide, and oxygen or carbon monoxide or a mixture thereof, in the presence of a free radical-producing means. Such treatment results in the formation of hydrogen sulfato groups at the structure surface. Preferably, the hydrogen sulfato groups are converted to ammonium sulfato groups by subsequent treatment with ammonia or a sufficiently basic amine.