Abstract: Stabilizers for organic polymers, consisting of one or more compounds of the classis of the sterically hindered amines (HALS) are directly added to the reaction mixture during the (co)polymerization of the .alpha.-olefins or of their mixtures with other unsaturated monomers.The so-obtained polymeric compositions result perfectly stabilized and show a thermo- and photo-oxidative resistance higher than that of the same polymeric compositions to which the same stabilizers are added by a traditional route.

Abstract: A process is disclosed for the synthesis of 4-allyloxy-2,2,6,6-tetraalkylpiperidinic derivatives by starting from the corresponding 2,2,6,6-tetraaLkyLpiperidinols and from an allyl halide, characterized in that the reaction is made to take place in the absence of water, and in the presence of a finely subdivided allyl-metal hydroxide and of small amounts of a phase-transfer catalyst. The products, which are thus obtained with yields higher than 90%, are useful a stabilizers for polymers or as intermediates for such products.

Abstract: Polymeric stabilizer compounds with a polyorganosiloxane structure suitable for stabilizing organic polymers against UV radiation and heat, containing sterically hindered piperidino groups in their molecule and easily prepared in well defined, predetermined structures.

Abstract: Reactive stabilizer compounds, to be used in the stabilization of organic polymers, contain a sterically hindered, N-substituted piperidinic, morpholinic or pyrrolidinic group, and at least a hydrolysable silicic function.Such compounds give rise, by hydrolysis of the silicic function, to complex resinous structures endowed with stabilizing properties.The reactive stabilizer compounds can spontaneously hydrolyse inside the polymer, or they can be stably supported on a solid support, or they can be chemically linked to the polymeric chain to be stabilized.

Abstract: Stabilizing inorganic fillers or pigments having simultaneous reinforcing effect and stabilizing effect on organic polymers are obtained by a process comprising the following stages:(a) bringing the inorganic filler or pigment into contact with a solution, in an inert organic solvent, of a sterically hindered amine comprising one or more alkoxysilane groups in its molecule;(b) maintaining the obtained mixture at higher than ambient temperature (20.degree.-25.degree. C.) for a period of at least 0.5 hours;(c) removing the solvent, treating at a temperature of 120.degree.-200.degree. C. and recovering the stabilizing filler or pigment obtained.

Abstract: A process is described for the preparation of N-allyl-2,2,6,6-tetraalkyl-piperidine derivatives which involves reaction of the corresponding 2,2,6,6-tetraalkyl-piperidine with an allylic carbonate in the presence of palladium catalysts. The products which are thus obtained are useful as polymer stabilizers and chemical intermediates.

Abstract: Stabilized polyolefinic compositions comprise a polyolefin, such as polyethylene and polypropylene and a stabilizing amount of an organic compound comprising at least one 3,3,5,5-tetramethylmorpholine or one 2,3,3,5,5-pentamethylene morpholine: ##STR1## wherein R is hydrogen or the methyl group; bearing a substituent on the carbon atom in the position 2 and/or on the nitrogen atom in the position 4 of the ring.