New hydrophilic photochromic polymeric systems containing side-chain azobenzene groups were synthesized by radical copolymerization of 4-acryloyloxyazobenzene with hydrophilic acrylic comonomers containing in the side chain either amide or quaternary onium groups. In all cases copolymerization products characterized by an almost random distribution of monomeric units were obtained. On irradiation at 366 nm, azobenzene-containing copolymers underwent trans-to-cis photoisomerization of the side-chain azo groups and in all cases monoexponential decay of the 320 nm absorbance was observed. Copolymer properties were investigated by DSC analysis, solubility measurements, UV spectroscopy and photoisomerization kinetics. The results obtained are discussed in terms of nature and content of hydrophilic comonomer and water content of the solvent used. The possibility of photomodulating copolymer solubility is also suggested.
Synthesis and photobehaviour of hydrophilic acrylic polymers containing azobenzene groups
ALTOMARE, ANGELINA;CIARDELLI, FRANCESCO;SOLARO, ROBERTO;
1995-01-01
Abstract
New hydrophilic photochromic polymeric systems containing side-chain azobenzene groups were synthesized by radical copolymerization of 4-acryloyloxyazobenzene with hydrophilic acrylic comonomers containing in the side chain either amide or quaternary onium groups. In all cases copolymerization products characterized by an almost random distribution of monomeric units were obtained. On irradiation at 366 nm, azobenzene-containing copolymers underwent trans-to-cis photoisomerization of the side-chain azo groups and in all cases monoexponential decay of the 320 nm absorbance was observed. Copolymer properties were investigated by DSC analysis, solubility measurements, UV spectroscopy and photoisomerization kinetics. The results obtained are discussed in terms of nature and content of hydrophilic comonomer and water content of the solvent used. The possibility of photomodulating copolymer solubility is also suggested.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
