Synthesis of Poly(glycidyl Methacrylate-r-photochromic Monomer) by ATRP

Abstract

The preparation of the random photochromic copolymer poly(glycidyl methacrylate-r-1′-(2-methacryloxyethyl)-6-nitro-3′,3′-dimethylspiro-[2H-1]-benzopyran-2,2′-indoline) by ATRP is reported, which can be used for the preparation of smart materials. Narrow homopolymers obtained from glycidyl methacrylate (GMA) are prepared when HMTETA-copper bromide and ethyl 2-methyl-2-bromo-propionate are used as the catalytic system with methyl-ethyl-ketone at 50°C. By using a molar ratio of 1:1 ligand:initiator, good correlations between experimental and theoretical molecular weights and narrow molecular weight distribution are obtained. These experimental conditions are also employed for the copolymerization of GMA with a photochromic monomer, where again good control of the polymerization reaction is obtained. The copolymer is fully characterized by spectroscopic techniques. The reactivity ratios are calculated according to the extended Kelen-Tüdos method, while the composition of the copolymer is calculated by NMR. Determination of r _GMA and r _PHM gives a value of 0.985 for GMA and 0.596 for the photochromic monomer.

Keywords:

• Photochromic copolymer
• ATRP
• glycidyl methacrylate
• spirobenzopyrane indoline

Acknowledgements

The authors are grateful to the Mexican Council of Science and Technology (CONACYT) for financial support through the project number 53186, to Lourdes Guillen Jose Guadalupe Telles and Julieta Sanchez for their helpful collaboration during the characterization of the reported molecules, and also to M. C. Sion NG from the Peace Corps for his valuable collaboration.