摘要:
The adhesion of polyolefin objects, in particular highly oriented polyethylene filaments, to, for instance, polar matrices is improved by oxidizing the surface of the objects and then treating it with a solution of a silane compound, a titanate or a chromium complex.
摘要:
Elongated object, made of an orientated alternating copolymer of carbon monoxide and an olefinically unsaturated monomer, which has a modulus of elasticity of at least 16 GPa, and a method for the production of objects from an alternating copolymer, orientated by stretching, of carbon monoxide and an olefinically unsaturated monomer, by dissolving the copolymer in a suitable solvent, converting the solution obtained, at a temperature above the dissolving point of the solution, to an object consisting of the solution, converting the object consisting of the solution to a solvent-containing object consisting of the copolymer, completely or partially removing the solvent from the solvent-containing object consisting of the copolymer and stretching at least the object thus obtained, or the solvent-containing object consisting of the copolymer, at elevated tempera-ture, it being possible for the stretching of tapes and films also to take place in two directions.
摘要:
The invention relates to microporous films of ultrahigh molecular weight polyethylene and to a process for the preparation thereof by forming a solution of UHMWPE in an evaporable solvent into a film and evaporating the solvent from the film at a temperature below the dissolution temperature, the shrinking tendency occurring in the film being prevented in at least one direction in the plane of the film.
摘要:
Process for stretching an article substantially consisting of a flexible-chain polymer, which is swollen in a solvent for that polymer, in which process an article substantially consisting of a copolymer of the polymer with a second polymer is swollen in a selective solvent for the flexible-chain polymer, and stretched, and an article containing an oriented flexible-chain polymer with a dichroic ratio of at least 1.1.
摘要:
The invention relates to articles consisting of highly oriented polyolefins having an ultrahigh molecular weight of more than 600,000 g/mol (weight-average molecular weight), especially filaments, fibers, yarns, fabrics and films, having good wetting and adhesive properties, especially on conventional matrix materials, which have been subjected to a plasma treatment of their surface, and also to a process for producing these articles and to their use for the manufacture of composites with the use of conventional matrix materials. In these composites, yarns according to the invention, for example, show a substantially higher adhesive strength than corresponding yarns which have not been plasma-treated, their tensile strength not being impaired by the plasma treatment.
摘要:
The invention relates to films of polymers of high molecular weight, which have been obtained by casting polymers dissolved or swollen in solvents and partially contain stiffened segments, which films serve either for decorative, handling or fixing purposes or allow, especially when formed on the film edges, a particularly ultrahigh stretching of the films without excessive formation of lips.
摘要:
High modulus and high strength articles of polyvinylalcohol are obtained by thermoreversible gelation of a 5-50 wt. % solution of a polyvinylalcohol with an M.sub.W of 2.5.times.10.sup.4 to 5.times.10.sup.5 in water, followed by solvent removal and high stretching.Pref. gelation is obtained by cooling to a temperature of at least 40.degree. C. below the gelation temperature.With this process low costs of solvent removal and regeneration are obtained.
摘要:
A process for producing an elongated object of an alternating copolymer of carbon monoxide and an olefinically unsaturated monomer wherein the copolymer has an intrinsic viscosity measured in m-cresol at 100.degree. C. of at least 1 dl/g, involve converting a solution of the copolymer into a solvent-containing object, removing between 90 and 99.9% of the solvent from the solvent-containing object, and stretching the thus obtained object at a temperature below the melting point of the copolymer.
摘要:
The invention relates to a process for the treatment of surfaces of highly oriented polyolefin objects, obtained by converting a solution or melt of a linear polyolefin with a weight average molecular weight of at least 400.000 g/mol, at a temperature above the dissolution temperature, respectively above the melting temperature, into a shaped object, converting this object into a gel-object by cooling, and stretching the gel-object at elevated temperature optionally after full or partial removal of the solvent, in which the surface of the object is contacted with a solution of a radical-forming compound and that the object is then exposed to a temperature of at least 30.degree. C. for at least 1 minute.
摘要:
The invention relates to polyolefin foams consisting of polyolefins of ultrahigh molecular weight, i.e. weight-average molecular weight from about 4.times.10.sup.5 to 6.times.10.sup.6 g/mol and higher, and to a novel process for producing these foams by foaming a solution of a polyolefin of ultrahigh molecular weight in a solvent with the use of a physical or chemical blowing agent or of an inert gas blown into the solution, and cooling of the resulting foam to a temperature below the gelling temperature of the polyolefin. If appropriate, these foams can be provided wholly or partially with a smooth skin on their surface by superficial cooling, if appropriate under the action of pressure. These foams are distinguished by high tensile strength and impact strength values, shock-absorbing properties, low glass transition temperatures, low embrittlement at low temperatures and high chemical resistance, and they are used especially as mechanical and acoustic insulating materials, materials of construction, filter agents and implantation materials.