The purpose of this paper is to evaluate the photochromic performance of photochromic compounds in polymer matrices.
The polystyrene films doped with photochromic fulgide were prepared and the effect of UV irradiation were studied using spectrophotometer. The reversible reaction was effected using white light. The effect of heat was also determined.
A film of the green coloured fulgide 2‐E doped in polystyrene polymer was irradiated with UV light (366 nm), the film turned blue. The latter colour was partially switched back to the original green colour when the film was irradiated with a white light. Increasing the annealing temperatures, increases the percentage conversion of 2‐C to 2‐E. The observed large bathochromic shifts in λmax of 2‐C and the partial conversion of 2‐C to 2‐E were rationalised on the bases of electronic and steric effects. It was found that both isomers 2‐C and 2‐E absorbed white light and they interconvert. The kinetics of photocoloration and photobleaching processes were followed spectrophotometrically by monitoring the absorbance of the ring closed product 2‐C at its λmax of 620 nm. The apparent first‐order rate constants for both processes were determined. It was found that there was slight variation in the rate constant for photocoloration reaction with annealing temperature. On the other hand, the apparent first‐order rate constant of the photobleaching reaction decreases with increasing the annealing temperature.
The polystyrene polymer doped photochromic fulgides described in the present paper was prepared and studied. The principle of study established can be applied to any type of polymer or to any type of photochromic compounds.
The photochromic materials developed can be used for different applications, such as coatings and holography.
The method developed may be used to enhance the performance of photochromic materials.
Bahajaj, A.A. and Asiri, A.M. (2008), "Photochromic properties of (E)‐3‐(2‐adamantylidene)‐2‐[5‐(4‐diethylaminophenyl)‐2‐methyl‐3‐furylethylidene] succinic anhydride doped in polystyrene film", Pigment & Resin Technology, Vol. 37 No. 3, pp. 140-144. https://doi.org/10.1108/03699420810870977
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