Ultraviolet stabilizing monomers and polymers. II. Synthesis and polymerization of acrylate and methacrylate derivatives of 2,4‐dihydroxybenzophenone

Abstract

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

Preparation and characterization of a high molecular weight UV‐stabilizer based on a derivative of 2,4‐dihydroxybenzophenone and its application in polymer materials

“…16 A mixture of 2,4-dihydroxybenzophenone (UV-0; 0.05 mol) and sodium hydroxide (0.155 g) were added into a 150 mL three-necked round-bottom flask with a stirrer, a refluxing condensation pipe, and a ventilation pipe. To exclude the oxygen gas, the reactor was deaired by vacuum pump and was aerated with nitrogen gas, and then, glycidyl methacrylate (GMA; 0.055 mol) was introduced into the reactor by syringe.…”

Preparation and evaluation of some benzophenone terpolymers as photostabilizers for rigid PVC

“…This moiety can reduce the incident light intensity and consequently delay the rate of the initiation reaction, thereby causing a slower rate of HCI evolution. The stabilizing effect of the 2‐hydroxybenzophenones [13–15] is attributed to their high absorbency in the wavelength range which is most harmful to polymers (300–350 nm), and they can harmlessly dissipate the absorbed energy by one or more nonradiative processes. The absorbed energy is dissipated by a mechanism that involves the reversible formation of a six‐membered hydrogen‐bonded ring.…”

Facile syntheses of 2,4‐dihydroxybenzophenone derivatives with polymerizable vinyl groups

“…2-Hydroxybenzophenones such as 2,4-dihydroxybenzophenone are excellent ultraviolet absorbers which can be incorporated into substrates such as plastics for the protection against degradative loss of their mechanical properties. Some attempts (1)(2)(3) have been made to synthesize vinyl derivatives of 2,4dihydroxybenzophenone which can be incorporated into polymer molecules by copolymerization, thereby preventing physical loss of the ultraviolet absorbing unit by evaporation during use. They are limited, however, to the modifications of 4-hydroxyl group of the benzophenone by esterification and etherification.…”