Abstract: Oil-repellent polymeric compositions prepared by a process which comprises:a) adding at least a radical starter and at least a perfluoropolyether to at least a molten thermoplastic polymer;b) intimately mixing the resulting composition for a time which is sufficient to obtain macroradicals from the polymer; andc) cooling the final composition to room temperature.

Abstract: A process for preparing thermoinsulating and structural formal articles in which(a) a thermoplastic polymer sheet is heated at a temperature above its softening point;(b) the heated thermoplastic polymer sheet is thermoformed on a thermoinsulating foamed preform made of substantially the same polymeric material; and in which(c) prior to the thermoforming in step (b), the thermoinsulating foamed preform is cooled to prevent excessive collapse of the surface of the thermoinsulating foamed preform resulting from contact with the heated sheet.

Abstract: A process for preparing structural, heat-insulating shaped bodies which does not necessarily require the use of a foamed heat-insulating material obtained by the use of blowing agents belonging to the class of chlorofluorocarbons. The process includes inserting a heat-insulating pre-molded core inside a tubular element made from an extruded thermoplastic polymer; placing the extruded tubular element containing the pre-molded core into a blow-molding mold; and molding the tubular element into a shell by blow-molding. By subsequent mold closure, the shell adheres to the pre-molded core. An alternative process is disclosed for adhering the tubular element and pre-formed core by closing the mold and drawing a vacuum within the tubular element.