聚醚改性聚硅氧烷.pdfVIP

European Polymer Journal 38 (2002) 65– 70 /locate/europolj Photosensitive crown ether–siloxane copolymers bearing azobenzene chromophores Rodinel Ardeleanu *, Anton Airinei, Gabriela Sacarescu, Liviu Sacarescu ‘‘Petru Poni’’ Institute of Macromolecular Chemistry, Aleea Grigore Ghica Voda 41A, 6600 Iasi, Romania Received 21 September 2001; received in revised form 1 April 2002; accepted 17 April 200 Abstract This paper presents the synthesis procedure of new photosensitive siloxane–crown ether copolymers using the polycondensation reaction of an oligosiloxane with COCl end groups and bisazo derivatives of dibenzo-18-crown-6 polyether. The azodiphenol compounds were prepared via the coupling reaction of 4,40 -diamine-DB18C6 diazonium salt with phenol or 1-naphthol. The polymers were characterized by IR absorption and 1H-NMR spectra as well as by thermal analysis and GPC. A study of the photoisomerization process as well as the thermal relaxation of azoaromatic chromophores in the polysiloxane–crown ether copolymer in dimethyl sulfoxide solution and of the corresponding complexes with KSCN was also presented. 200 2Elsevier Science Ltd. All rights reserved. 1. Introduction azobenzene chromophore the crown unit has weak co- ordination ability for metal cations. UV irradiation A wide variety of polymers and copolymers containing produces the trans–cis isomerization of the chromo- photochromic molecules such as azobenzene, have been phore giving a supramolecular