McGrath Alaina J, Shi Weichao, Rodriguez Christina G, Kramer Edward J, Hawker Craig J, Lynd Nathaniel A
Materials Research Laboratory, University of California, Santa Barbara, CA 93106, USA.
Materials Research Laboratory, University of California, Santa Barbara, CA 93106, USA ; Materials Department, University of California, Santa Barbara, CA 93106, USA ; Department of Chemical Engineering, University of California, Santa Barbara, CA 93106, USA.
Polym Chem. 2015 Mar 7;6(9):1465-1473. doi: 10.1039/C4PY01503G.
We report an effective strategy for the synthesis of semi-crystalline block copolyethers with well-defined architecture and stereochemistry. As an exemplary system, triblock copolymers containing either atactic (racemic) or isotactic ( or ) poly(propylene oxide) end blocks with a central poly(ethylene oxide) mid-block were prepared by anionic ring-opening procedures. Stereochemical control was achieved by an initial hydrolytic kinetic resolution of racemic terminal epoxides followed by anionic ring-opening polymerization of the enantiopure monomer feedstock. The resultant triblock copolymers were highly isotactic (meso triads []% ~ 90%) with optical microscopy, differential scanning calorimetry, wide angle x-ray scattering and small angle x-ray scattering being used to probe the impact of the isotacticity on the resultant polymer and hydrogel properties.
我们报道了一种合成具有明确结构和立体化学的半结晶嵌段共聚醚的有效策略。作为一个示例性体系，通过阴离子开环程序制备了含有无规（外消旋）或全同立构（或）聚环氧丙烷端基块和中心聚环氧乙烷中间块的三嵌段共聚物。通过对外消旋末端环氧化物进行初始水解动力学拆分，然后对纯对映体单体原料进行阴离子开环聚合，实现了立体化学控制。所得的三嵌段共聚物具有高度全同立构性（内消旋三单元组[]%~90%），利用光学显微镜、差示扫描量热法、广角X射线散射和小角X射线散射来探究全同立构性对所得聚合物和水凝胶性能的影响。
