Novel calamitic side-chain metallomesogenic polymers with ferrocene in the backbone: synthesis and properties of thermotropic liquid-crystalline poly(ferrocenylsilanes)
Novel calamitic side-chain metallomesogenic polymers with ferrocene in the backbone: synthesis and properties of thermotropic liquid-crystalline poly(ferrocenylsilanes)
Functionalization of poly(metallocenes) via hydrosilylation: synthesis and properties of thermotropic liquid crystalline poly(ferrocenylsilanes)
作者:Xiao-Hua Liu、Duncan W. Bruce、Ian Manners
DOI:10.1016/s0022-328x(97)00254-4
日期:1997.12
Hydrosilylation of poly(ferrocenylmethylhydrosilane) [Fe(η-C5H4)2SiMeH]n with 1-hexene and ethyl acrylate was achieved using Karstedt's catalyst with degrees of functionalization of ca 80%. Using a similar strategy, 4-pentoxy-4′-hydroxyhexanoxyazobenzene or 4-pentoxy-4′-hydroxyundecyloxyazo-benzene acrylate side chains were successfully attached to the poly(metallocene) mainchain. The resulting functionalized
聚(ferrocenylmethylhydrosilane)的氢化硅烷化的[Fe(η-C 5 H ^ 4)2 SiMeH] Ñ与1-己烯和丙烯酸乙酯使用的Karstedt的配合度的CA 80%官能化的催化剂来实现的。使用类似的策略,将4-戊氧基-4'-羟基己氧基偶氮苯或4-戊氧基-4'-羟基十一烷基氧基偶氮苯丙烯酸酯侧链成功连接到聚(茂金属)主链上。所得的官能化的聚(二茂铁基硅烷)代表骨架中具有二茂铁基团的热敏性热侧链液晶聚合物的第一个实例。
The Initial and Photoinduced 3D Orientational Order in Polymethacrylates with Azobenzene Side Groups
作者:O. Yaroshchuk、T. Bidna、O. Nadtoka、L. Olkhovyk、V. Syromyatnikov、L. C. Chien
DOI:10.1080/15421400590954353
日期:2005.6.1
The combination of the transmission null ellipsometry and total absorption method, earlier approved for several polymer classes, is applied to study 3D orientational configurations of azachromophores in polymethacrylates with azobenzene side groups. The transformation of the initial orientation due to the photoexcitation of azoehromophores is investigated. The dependence of the orientational configuration on the structure of azochromophore fragments and its concentration in the polymers are also studied. In the non-irradiated films, azochromofores strive to be aligned normally to the film plate. Under irradiation, if reorientation mechanism of the photoinduced ordering prevails, the azochromophores reorient perpendicularly to the polarization direction of the exciting light, E-ex, and in the saturation state they are randomly distributed in the plane perpendicular to E-ex This implies that the induced structure is mainly influenced by the photoordering, while selfordering of polymer chains is not effective or overcome, presumably because of high T-g of polymethacrylates. In case when photoselection ordering mechanism dominates, 3D distribution of azochromophores in the saturation state of irradiation is isotropic due to a strong exhaustion of the number of anisotropic trans isomers. The transient photoinduced orientations are biaxial independently on the dominating ordering mechanism. The reduction of the azochromophore's concentration in polymers reduces the anisotropy rate but not influence the trends described above. The observed regularities were earlier described for several other classes of photosensitive polymers and so they may be common rules for photoordering in the photochromic media.