Synthesis and characterization of new photostabilizers from 2,4-dihydroxybenzophenone p H. Seliger a , E. Happ a , A. Cascaval b, *, L. Birsa b , T. Nicolaescu b , I. Poinescu c , C. Cojocariu c a University of Ulm, Sektion Polymere, Albert-Einstein-Alee 11, D-89081 Ulm, Germany b ``Al.I. Cuza'' University of Iasi, B-dl Copou 11, RO-6600 Iasi, Romania c ``P. Poni'' Institute of Macromolecular Chemistry, Gr. Ghica Voda Alley, RO-6600 Iasi, Romania Received 11 September 1997; accepted 26 November 1997 Abstract Two new polymerizable stabilizers, 4-benzoyl-2-(a-piperidino-2-chlorobenzyl)-3-hydroxyphenyl acrylate (BPBHA) and corresponding methacrylate (BPBHMA), were synthesized and characterized. They were copolymerized with styrene in dierent molar ratios to obtain new polymeric materials with self-protection against UV radiation. The eciencies of BPBHA and BPBHMA as ultraviolet stabilizers were examined by studying the change of the inherent viscosity of the copolymers during the exposure of the copolymer to UV irradiation. # 1999 Elsevier Science Ltd. All rights reserved. 1. Introduction The polymeric materials are submitted to a photoox- idative degradation during their utilization and depo- sition is under atmospheric conditions. The initiation of this degradation is caused by the impurities and functional groups able to absorb the radiation energy which results in excited states suering further photo- chemical reactions [1, 2]. The noticeable eects of these reactions are the decrease in the tensile strength, the increase of elongation at break, the discoloring which ®nally deter- mines a strong diminution of the utilization of these materials. The main methods applied for polymer pro- tection against the sun radiation are based on mixing these polymers with low-molecular weight organic compounds such as those absorbing within the UV domain where the photodegradation take place or those trapping the free radicals formed during the ®rst stage of the photodegradation. Where the surface/ volume ratio of the polymeric materials is high (e.g. ®lms, ®bers) these additives show the tendency to physical losses by leaching or evaporation due to their rather low molecular weights and reduced polymer/ additive compatibility. A great deal of eorts have been made in recent years for obtaining stabilizers of a better compatibility and higher molecular weight showing a lower mi- gration tendency in comparison to the additives with low-molecular weights [3±7]. The homopolymerization and copolymerization of the monomers containing functional groups with UV absorbing and antioxidiz- ing properties represents the most widely applied methods for preparing of the photostabilizers of high molecular weight [8±10]. The chemistry of Mannich bases oers convenient and useful ways for the syn- thesis of various compounds mainly based on phenolic European Polymer Journal 35 (1999) 827±833 0014-3057/99/$ - see front matter # 1999 Elsevier Science Ltd. All rights reserved. PII: S0014-3057(98)00069-X PERGAMON p This work is dedicated to Professor Dr. Hans-Joachim Cantow on his 75th anniversary. * Corresponding author.