POLYMERIC MATERIAL FOR THE MANUFACTURE OF RUBBER MOULDINGS AND RUBBER CASTINGS, FOR EXAMPLE, FOR GEARS, CARTON BLOCKS, FUNNELS, ROLLERS, ELEVATOR GUIDE WHEELS, MALLET HEADS, SUCTION CUPS, PRINTING ROLLS, TRUCK WHEELS, VALVES, CUTTING AND FORMING DIES, INDUSTRIAL WHEELS AND TIRES, ROLLER SKATE WHEELS AND THE LIKE