结晶性间同立构1,2-聚丁二烯的单晶结构  

Single Crystal Structure of Crystalline Syndiotactic 1,2-Polybutadiene

作　　者：陈晔[1] 杨德才[1] 胡雁鸣 张学全 

机构地区：[1]中国科学院长春应用化学研究所高分子物理与化学国家重点实验室 [2]高分子工程实验室,长春130022

出　　处：《高等学校化学学报》2003年第12期2321-2323,共3页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金 (批准号 :2 0 2 3 40 2 0 );国家重大基础研究发展规划项目 (批准号 :G19990 64 80 5 )资助

摘　　要：The crystalline syndiotactic 1,2-polybutadiene was synthesized with a catalytic system consisting of iron acetylacetonate , triisobutylaluminum and diethyl phosphite (DEP), and its single crystal structure was studied by transmission electron microscopy (TEM) and electron diffraction (ED) techniques. The polymer with melting point 179 ℃ was found to have 89.3% 1,2 content and 86.5% sydiotacticity based on 13C NMR measurement. The single crystals of the polymer were achieved by melt crystallization of the solution cast thin films at 150 ℃ for 2 h. Bright field electron micrograph shows that the single crystal exhibits a hexagonal prism shape with its long axis along the crystallographic b-axis, as revealed by the corresponding ED pattern. The strong (hk 0) reflections of the ED pattern indicate that the single crystal possesses a very good crystallographic orientation with the c-axis perpendicular to the film plane. According to the orthorhombic packing of the planar zigzag chains, all of the diffraction points can be indexed, and the unit cell parameters calculated from the ED result are a=1.102 nm and b=0.664 nm. In order to obtain the unit cell parameter c, α highly oriented thin film of the polymer was prepared with a special melt drawn technique. The TEM bright field image indicates that the melt drawn thin films contain highly oriented lamellae with their growing direction perpendicular to the drawing direction. The corresponding ED pattern reveals the molecular chains are highly oriented, with the c-axis parallel to the drawing direction. The unit cell parameter c is 0.513 nm, as calculated from the (hk 0) reflections.The crystalline syndiotactic 1,2-polybutadiene was synthesized with a catalytic system consisting of iron acetylacetonate , triisobutylaluminum and diethyl phosphite (DEP), and its single crystal structure was studied by transmission electron microscopy (TEM) and electron diffraction (ED) techniques. The polymer with melting point 179 ℃ was found to have 89.3% 1,2 content and 86.5% sydiotacticity based on 13C NMR measurement. The single crystals of the polymer were achieved by melt crystallization of the solution cast thin films at 150 ℃ for 2 h. Bright field electron micrograph shows that the single crystal exhibits a hexagonal prism shape with its long axis along the crystallographic b-axis, as revealed by the corresponding ED pattern. The strong (hk 0) reflections of the ED pattern indicate that the single crystal possesses a very good crystallographic orientation with the c-axis perpendicular to the film plane. According to the orthorhombic packing of the planar zigzag chains, all of the diffraction points can be indexed, and the unit cell parameters calculated from the ED result are a=1.102 nm and b=0.664 nm. In order to obtain the unit cell parameter c, α highly oriented thin film of the polymer was prepared with a special melt drawn technique. The TEM bright field image indicates that the melt drawn thin films contain highly oriented lamellae with their growing direction perpendicular to the drawing direction. The corresponding ED pattern reveals the molecular chains are highly oriented, with the c-axis parallel to the drawing direction. The unit cell parameter c is 0.513 nm, as calculated from the (hk 0) reflections.

关 键 词：结晶性 间同立构 1 2-聚丁二烯 单晶结构 电子衍射技术 

分 类 号：O632.12[理学—高分子化学] O631.13[理学—化学]