Abstract: In a first stage, a lactone is polymerized by an ionic route in vinyl chloride with the aid of a catalyst consisting of the product, optionally complexed with tetrahydrofuran, of the reaction of an alkylmetal with ethylenically unsaturated alcohol, optionally in the presence of water and, in a second stage, the said vinyl chloride is polymerized by a radical route in an aqueous suspension and in the presence of the polymerization medium originating from the first stage, to which other unsaturated monomers are optionally added.The invention also relates to new modified vinyl chloride polymers consisting of lactone polymers whose number-average molecular weight is less than 5,000, grafted with vinyl chloride polymers.

Abstract: The compositions contain, as vinyl chloride polymers, copolymers of vinyl chloride and of alkyl acrylates in which the alkyl radicals, consisting of linear or branched chains, contain from 1 to 10 carbon atoms and have an initial Shore A hardness not exceeding 85. They are suitable for the production of very diverse flexible articles, especially in the medical field (pouches for blood and for physiological fluids), the motor vehicle field (various profiles and seals) and the building industry (sealing sheets).

Abstract: In a first stage, a heterocyclic oxygen compound is polymerized by an ionic route in a vinyl halide and, in a second stage, the vinyl halide, to which other unsaturated monomers capable of being polymerized by a radical route may be added if desired, is polymerized by a radical route in aqueous dispersion and in the presence of the polymerization mixture originating from the first stage.

Abstract: A process for the manufacture of alkylacetophenones wherein (1) benzene is acylated, (2) the alkylaryl ketone thus obtained is hydrogenated catalytically, and (3) the alkylbenzene thus obtained is acetylated, in only one solvent chosen from among chlorinated aliphatic hydrocarbons containing 1 to 3 carbon atoms and 2 or 3 chlorine atoms per molecule, and their mixtures.

Abstract: Phosphorus-containing halogenated unsaturated polyester compositions are prepared by heat treating halogenated unsaturated polyesters derived from at least one epihalohydrin and maleic anhydride. The heat treatment is carried out in the presence of an organic phosphite at a temperature of between 50.degree. and 200.degree. C.

Abstract: Super-halogenated unsaturated polyesters having average molecular weights of between 300 and 3,000, comprising units derived from at least one .alpha.-epihalohydrin and from maleic anhydride and optionally from another cyclic organic anhydride, possessing a halogen content arising from super-halogenation of between 1 and 35% by weight and the process for their manufacture which is characterized in that maleic anhydride, alone or mixed with another cyclic organic anhydride, is copolymerized with at least one .alpha.-epihalohydrin in molar ratios of epihalohydrin to anhydride(s) of between 1:1 and 2:1, in the presence of a titanium tetrahalide, the halogen being preferably chosen from the group consisting of chlorine and bromine.