Process for obtaining ultra-high modulus products

A method for producing high-modulus semicrystalline polymer products comprising:

• Solid-state extruding a polymer having an initial polymer morphology by feeding under pressure through an extrusion-rotation die having a static entry position and a succeeding friction-reducing moving portion, said succeeding friction-reducing moving portion of said die comprising a pair of oppositely rotating members, each having integral, shaped wall surfaces strictly confining, engaging, and compressing the entire perimeter of the polymer during extrusion and providing the geometry of a die exit and a profile for extrudate which has practically the same cross-sectional area and lateral dimensions as the cross-sectional area and lateral dimensions of the die exit, said static and succeeding friction-reducing moving portions of the die having a polymer-containing zone with convergent geometry through which the polymer is compressed, oriented, and extruded under conditions of minimal friction between the polymer and the die surface for reducing the extrusion pressure, said minimal friction being obtained by substantially synchronous movement of the rotating members of the die and the polymer, said extrusion being at a temperature near but below the crystalline melting point of said polymer, to obtain an extruded polymer product having a markedly transformed morphology as compared with said initial polymer morphology, comprised of oriented and extended molecular chains and markedly enhanced tensile properties, the values of which are for the Young's modulus within the range of 2 to 220 GPa and for the tensile strength within the range of 0.15-4 GPa, and which depend upon the extent of the cross-sectional area reduction during extrusion.