摘要:
This invention provides novel polymers which contain discrete photoconductive and electrooptic moieties. The moieties may exist as part of the main chain of the polymer or as pendant side chains. The polymers have utility as transparent photorefractive media in photorefractive devices.An invention polymer where both the photoconductive and electrooptic moieties exist as pendant side chains is illustrated by the copolymer of the following structure: ##STR1##
摘要:
A moldable hollow glass filled PBI composition. The composition may be prepared by making a well-mixed slurry of glass microspheres in a solution of PBI in a suitable solvent, and then spinning the slurry through a jet or die under pressure and into a water bath where the particles coagulate. The solvent dissolves in the water, allowing solvent-free PBI-glass composite particles to be isolated.
摘要:
Pseudo network polymer is characterized by a network of linear segments which is composed of recurring units of a multivalent branching moiety, a chain-defining moiety, and a coupling moiety. The polymer may be formed into film, fiber and molded articles which exhibit improved mechanical properties in the transverse direction.
摘要:
A melt processable wholly aromatic liquid crystalline polymer capable of forming an anisotropic melt phase at a temperature below approximately 400.degree. C. having enhanced adhesion properties containing from approximately 0.05 to approximately 2.0 mole percent of a recurring sulfonated, ionic moiety in the backbone of the polymer. The polymer is useful for the production of laminate structures.
摘要:
Ceramic fibers formed by the pyrolysis of organosilicon preceramic polymers are provided with increased resistivity by treating the fibers in air at temperatures of less than 1,000.degree. C. to oxidize the free carbon content of the fibers.
摘要:
A process for preparing shaped polybenzimidazole sintered products having increased resistance to dimensional modification by absorption of water and the products prepared therefrom.
摘要:
The invention discloses oligomeric compositions that have high thermal and uv stability as well as reactive end groups so that they may be reactively incorporated into polymer backbones when the polymers are prepared. The oligomeric moieties are capable of retaining their chemical structure intact at temperatures where the polymers are processed into articles, so that the finished articles contain the oligomeric moieties and possess good stability towards ultraviolet light. An example of such oligomer is illustrated by the following poly(aminoterephthalic acid). ##STR1##
摘要:
Fine, porous polybenzimidazole-containing particles prepared by spray-atomizing/quenching a polybenzimidazole-containing polymer solution into porous polybenzimidazole-containing particles, and fluidized bed, oppose jet milling the particles into fine, porous polybenzimidazole-containing particles. The milled particles exhibit a narrow particle size distribution centered at about a 5 .mu.m mean particle size, a surface area of about 35 m.sup.2 /g, and an open porosity of about 1.2 cm.sup.2 /gm which is at pore radius of less than about 100 nm.
摘要:
An optical fiber bundle 10 is disclosed including a plurality of polymer optical fibers 12 disposed within a rigid sleeve 14. The fibers have been drawn to a draw ratio of at least 1:1.5 prior to placing them within the sleeve, whereupon the structure 13 is heated to induce elastic relaxation of the fibers which contract in length and expand in girth. The expansion within the rigid sleeve results in a close-packed geometry.
摘要:
A moldable thermoset composition comprising about 5-60% liquid crystal polymer and about 95-40% of an epoxy-functional rubber by weight, a process for making and a process for using same. The composition is made by melt mixing the LCP and the epoxy-rubber to form a blend. This blend is then cooled and may be molded, extruded, or otherwise formed into a desired shape. The composition is then heat-treated to make it set.