BARRIER PROPERTY OF AZOBENZENE-CONTAINING SIDE-CHAIN LIQUID CRYSTALLINE POLYMER

In order to study the properties of azobenzene-containing side-chain liquid crystalline polymer for preventing the permeation of small molecule, poly (3-[4-(4'-cyanophenylazo) phenoxy] propyl methacrylate) (PM3ABCN) was synthesized in this study. The barrier properties of PM3ABCN was individually determined using in-situ glancing incidence X-ray diffraction (GIXRD) scanning technology under the amorphous state and the liquid crystalline (nematic) state. GIXRD was used to collect the metal surface oxidation, which is a quantitative result of oxygen permeated through the polymer films covering the metal surface. The content of oxygen element in oxidized iron matrix samples was analyzed by means of X-ray energy dispersive spectroscopy (EDS), and the amount of oxygen permeated through the synthesized polymer films was calculated based on the results gained from the XRD patterns and EDS analysis. The results indicated that the average permeation rate of oxygen through the PM3ABCN films was 1.92 x 10(-3) cm(3)day(-1) m(-2) and 4.38 x 10(-4) cm(3)day(-1) m(-2) under the isotropic phase and liquid crystalline phase respectively, and the permeation property of liquid crystalline PM3ABCN was 4. 4 times slower than that of the amorphous state. In combination with the results of microscopic analysis on the specimen surface, the barrier mechanism of condensed state structure in liquid crystalline PM3ABCN was also investigated.