Abstract: Fluorinated polymers having improved mechanical properties and an improved surface appearance, characterized in that they comprise a reinforcing material based on glass, asbestos and silicates in general or carbon, in the form of fibres or granules, or polyamidic fibres, such material being superficially treated with fluoropolyethers having an average molecular weight from 1,000 to 10,000 and containing functional end groups capable of forming bonds of various nature with the reinforcing material.

Abstract: Fluoroelastomeric compositions based on vinylidene fluoride, having a high adhesion to metals in the vulcanized state, and characterized in that they contain small amounts of chlorotrifluoroethylene which is present as a comonomer of an elastomeric copolymer of vinylidene fluoride.

Abstract: Covering element having selective optical properties, suited as a protective screen for refrigerating devices by radiation, consisting of at least one film or sheet of a material, transparent to infrared radiation comprised between 8 and 13.mu.m, and selected among polyethylene and ethylene copolymers, additioned with coloring materials selected among pigments and dyes so as to make this film reflecting in a prevailingly diffusive way (white) on the face to be turned to the direct solar radiation and absorbent, that is dark, for wave lengths below 3.mu.m on the opposite face, said film thus additioned showing a mean weighted reflectance in the solar spectrum greater than 0.6 on the upper face exposed to the sun and less than 0.3.mu.m on the opposite face, as well as a mean weighted transmittance in the solar spectrum not exceeding about 0.1.