摘要:
Certain polyester-based polyurethaneureas in solutions of organic solvent at a 12 to 20% concentration are particularly suited for use in a mandrel-dipping process for producing thin-walled elastic articles, such as surgical gloves, which are more resistant to puncture and tear than conventional surgical gloves made from rubber latex.
摘要:
Heat aging of the composition comprising melt-fabricable tetrafluoroethylene/perfluoro(alkyl vinyl ether) copolymer, the alkyl containing 1 to 5 carbon atoms and melt flowable polytetrafluoroethylene is effective to cause thermal transformation of the composition in the solid state, which is epitaxial co-crystallization of the polymer components of the composition, and other valuable changes, such as increased continuous use temperature.
摘要:
A process is provided for improving the MIT flex life of tetrafluoroethylene/perfluoro(alkyl vinyl ether) copolymer, said perfluoroalkyl containing from 1 to 5 carbon atoms, comprising incorporating melt flowable polytetrafluoroethylene into said copolymer and thereafter heat treating the resultant composition at a temperature of at least 280° C., the amount of said polytetrafluoroethylene and said heat treatment being effective to increase the flex life of said composition by at least 2× the flex life of both said copolymer and said composition prior to said heat treatment and to thermally transform the composition in the solid state, which is epitaxial co-crystallization of the polymer components of the composition.
摘要:
Creep resistant fluoropolymer is made by blending a melt-fabricable fluoropolymer having a melt flow rate of no greater than about 7 g/10 min with milled carbon fiber and forming the resultant blend into an article, the carbon fiber content of the blend being from about 15 to 35 wt % based on the combined weight of the carbon fiber and the fluoropolymer.
摘要:
Communications cable is provided for use in downhole wells wherein the cable will be exposed to a temperature of at least 280° C., the cable including as a component thereof a composition comprising melt-fabricable tetrafluoroethylene/perfluoro(alkyl vinyl ether) copolymer and melt flowable polytetrafluoroethylene, said polytetrafluoroethylene by itself having no tensile property and being present in said composition in an amount effective to enable the component to withstand this temperature, with the high temperature exposure of the cable component being effective to thermally transform the composition in the solid state, thereby obtaining epitaxial co-crystallization.
摘要:
A composition of tetrafluoroethylene/perfluoro(ethyl vinyl ether) copolymer particles and metal powder is disclosed that enables the composition to be used for adhering a lining to an interior surface of a hollow article.
摘要:
A process is provided for rotolining the interior surface of an oil pipe having an inner diameter of at least 2 in (5.1 cm) and no greater than 6 in (15.2 cm) and length of at least 10 ft (3 m), comprising introducing particles of rotolining composition comprising fluoropolymer and no greater than 2 wt % of metal powder into the interior of said pipe, heating the pipe to a temperature above the melting temperature of the fluoropolymer, rotating the pipe around its longitudinal axis during the heating and rocking the pipe end-to-end thereof during the rotating so as to distribute the composition over the entire interior of the pipe, the combination of heating and distributing causing the particles to melt and coalesce to form a rotolining on the pipe over its entire interior.
摘要:
The present invention relates to a composition of tetrafluoroethylene/perfluoro(ethyl vinyl ether) copolymer particles and metal powder which enables the composition to the used for rotolining an interior surface of a hollow article, wherein the resultant lining adheres to such surface. The invention further relates to oil pipe having its interior surface rotolined with fluoropolymer, the rotolining containing an effective amount of metal powder to cause the rotolining to adhere to said interior surface and a process for rotolinig the interior of the oil pipe.
摘要:
Carbon fibers having balanced properties comprising an ultra-high modulus greater than 100 Mpsi and a high tensile strength of greater than 500 kpsi. The carbon fibers are derived from a solvent fractionated pitch having a mesophase content of greater than 90% by weight and a quinoline insolubles content of less than 1% by weight. A crude pitch feed is sequentially heat soaked, solvent fractionated, and extruded to form as-spun fibers. The latter are stabilized or infusibilized and then carbonized by multistage heat treatments involving separate precarbonization, carbonization, and graphitization steps with an intermediate cooling step.
摘要:
The present invention relates to a preformed liner of tetrafluoroethylene/perfluoro(alkyl vinyl ether) copolymer adhered to the surface of a pipe, and in particular, an oil well pipe, without the need for either a primer layer or an adhesive. The liner comprises an effective amount of metal powder which provides adhesion between the liner and the surface of the pipe. The present invention also relates to a process for making such pipe, where in a preferred embodiment, the liner is co-extruded to form an inner layer and an outer layer. This co-extrusion embodiment is particularly useful in applications where high purity is necessary. In this case, the inner layer comprises an effective amount of metal powder and the outer layer is pure tetrafluoroethylene/perfluoro (alkyl vinyl ether) copolymer.