Abstract: Improved films that contain molecular composites or block copolymers of lyotropic liquid crystalline polymer and thermoplastic polymer can be made by the steps of:(1) washing a dope film, that contains a solvent and the molecular composite or block copolymer;(2) stretching the wet, never-dried film from Step (1) in at least one direction; and(3) drying the film from Step (2).The films have improved mechanical properties and can be used in structural applications.

Abstract: An apparatus for the constrained drying and/or heat treating of a continuous or roll of, web stock of film. This apparatus includes a mechanism which grasps a film by its edges and moves said film through a drying zone, with said mechanism holding said film taut without substantial stretching of said film in the drying zone, and a means to remove the evaporated solvent from said apparatus. The apparatus is particularly useful for drying film of polybenzoxazole, polybenzothiazole and copolymers thereof, as well as molecular composite films. A method of drying/heat treating film is also disclosed.

Abstract: Granular compositions which comprise a block copolymer containing blocks of polybenzazole polymer and blocks of thermoplastic polymer can be compression molded to provide a molded article having physical properties superior to molded articles made from the thermoplastic polymer alone.

Abstract: Fibers may be prepregged with a dope containing a thermoplastic polybenzazole block copolymer. The prepreg may be contacted with water or another nonsolvent to coagulate the polymer and form a matrix composite.

Abstract: Granular compositions which comprise a block copolymer containing blocks of rigid rod polybenzazole polymer and blocks of thermoplastic polybenzazole polymer can be compression molded to provide a molded article having physical properties superior to molded articles made from the thermoplastic polymer alone.

Abstract: Compositions comprising thermoplastic polymers having added thereto small amounts of a hydroxymethyl-substituted carboxylic acid are usefully employed to remove accumulated polymeric residues from polymer processing equipment.

Abstract: A method for preparing a polymeric laminate by the reactive coextrusion of functionalized polymers wherein at least one layer is a polymer having functional groups and the adjacent layer is a polymer having coreactive groups which form covalent bonds with the functional groups at the interfacial surfaces. One such functional group can comprise a pendant cyclic imino ether group to form covalent bonds with the coreactive groups. A laminate having a plurality of layers covalently bonded together through the interaction of pendant cyclic imino ether groups and coreactive groups is also provided.