Effect of Dendritic Architecture on Photochromism of Spiropyran Functionalized Dendrigraft Polybutadiene

摘要

This paper demonstrated the photochromic behavior of two novel spiropyran functionalized dendrigraft polybutadiene with linear-comb and star-comb architectures (LC-PB-Sp and SC-PB-Sp, respectively). LC-PB-Sp and SC-PB-Sp were synthesized via the combination of anionic polymerization and "click" chemistry methodology. The photochromic behavior was investigated based on UV-Vis spectroscopy. The results showed that the coloring speed was in an order of v(Sp) > v(SC-PB-Sp) > v(LC-PB-Sp), while the discoloration speed exhibited in an order of v(SC-PB-Sp) > v(LC-PB-Sp) > v(Sp), suggesting that the nonpolar dendritic PB matrices tended to stabilize the nonpolar closed form of spiropyran. Furthermore, the retrieval rate of SC-PB-Sp was much faster than its corresponding LC-PB-Sp due to its more compact structure.