synopsisWith a view to permanently incorporating ultraviolet stabilizing moieties into polymer systems, monomew containing the phenyl salicylate structure have been prepared and polymerized. Phenyl 5acryloxymethylsalicylate and phenyl 5methacryloxymethyl-salicylate were prepared by the chloromethylation of phenyl salicylate and subsequent reaction with sodium acrylate or methacrylate. Homopolymers and copolymers of the methacryloxymethyl monomer were prepared and studied. The ultraviolet spectra of the chloromethyl derivative, the monomers, and the homopolymers were essentially similar to that of the starting material, phenyl salicylate. Copolymers of the ultraviolet-absorbing monomers (2%) with vinyl acetate, vinylidene chloride, and vinyl chloride were prepared. The ultraviolet stability of these copolymers was then compared to that of an unstabilized control series and a series containing phenyl salicylate. While there were some differences in the behavior of the copolymerized absorber it was a t least as effective m phenyl salicylate in stabilizing the polymers.The advantage of an ultraviolet stabilizing moiety chemically attached to the substrate has been generally recognized in the past few years. Such problems as migration, volatility on prolonged exposure to exterior conditions, compatibility, and toxicity should be minimized by this approach. Recent patent literature' cites examples, wherein vinyl and ally1 esters of salicylic acid are copolymerized and thus permanently attached to the polymeric substrate. The use of salicylates as ultraviolet absorbers is well known12+ and phenyl salicylate has, in particular, been extensively used for the stabilization of poly(viny1idene chloride)6 and to a more limited extent for poly(viny1 chloride) 2 and polyolefins.I n this work, the approach to the preparation of ultraviolet absorbing monomers has been to use the phenyl salicylate moiety, and to attach onto it, by fairly simple organic reactions, acrylate and methacrylate groups [es. (1) 1.
SynopsisIn the addition of stabilizing agents to plastic materials, problems such as incompatibility, migration, volatility, and/or solvent extraction of the additive frequently arise. With a view toward overcoming such problems in the use of ultraviolet absorbing stabilizers, acrylate and methacrylate derivatives containing the 2-hydroxy-4alkoxybenzo-phenone moiety have been synthesized. The ultraviolet absorbing monomers were synthesized by reaction of 2,4-dihydroxybenzophenone with glycidyl acrylate and glycidyl methacrylate. They were homopolymerized and blended with poly(viny1 chloride), poly( vinylidene chloride), polystyrene, and poly( methyl methacrylate). They were also copolymerized with the corresponding monomers. The polymer blends and copolymers were investigated for ultraviolet stability versus corresponding controls. Effective ultraviolet stabilization was observed. Differences in the stability of some blends as compared t o corresponding copolymers is thought to be due to incompatibility.In recent years there has been increasing interest in the synthesis of ethylenically unsaturated ultraviolet absorbers which could be copolymerized, thereby permanently incorporating a stabilizing moiety into a polymer. This approach would minimize problems such as incompatibility, migration, volatility, and solvent extraction. The patent literature
Stepwise replacement of halogen in phosphorus trihalides has been effected by alkoxytrimethylsilanes, thus avoiding the presence of hydrogen halides or tertiary base. The 1-phenylethoxysilane afforded the dichloridite, but the tert.-butoxy-analogue gave only alkyl chloride. Replacement in the oxychloride proceeded to the dichloridate, and much more slowly to the chloridqe, and there was evidence of formation of n-butyl phosphorodibromidate from the oxybromide. Fission of the alkoxysilane occurred differently in the examples of the 1-phenylethyl and diphenylmethyl derivatives , the oxychloride affording alkyl chloride and trimethylsilyl phosphorodichloridate.REPLACEMENT of halogen in phosphorus trihalides and oxyhalides by the alkoxyl group has been effected by alkoxytrimethykilane under conditions in which the presence of a tertiary base and a hydrogen halide is avoided. Certain limitations have been observed. Thus stepwise replacement of halogen in the trichloride by alkoxyl was effected by n-butoxytrimethylsilane , giving the alkyl phosphorodichloridite, the dialkyl phosphorochloridite, and the trialkyl phosphite [scheme (l)] . n-, iso-, and sec.-Butyl phosphorodibromidites, and the corresponding bromidites were prepared from phosphorus tribromide. The halogenotrimethylsilane formed concurrently was readily separated and used for the preparation of further supplies of the alkoxysilane.
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