93. Evolution of crystal patterns of single-layer lamellae of star-shaped PEOs
作者：Gou-liang Zhang, Xiao-jing Wen, Xue-mei Zhai, Wei Wang
關鍵字：Poly(ethylene oxide) crystallization pattern formation star-shaped polymers
論文來源：期刊
具體來源：Acta Polymerica Sinica
發表時間：2012年
In this work the study on evolution of crystal patterns of single-layer lamellae of three star-shaped poly(ethylene oxide)s (PEO) samples with 3, 4 and 8 arms and a 5000 g/mol molecular weight for each arm and a 5000 g/mol linear PEO sample were reported. With increasing crystallization temperature the dendritic-to-seaweed and seaweed-to-faceted crystal pattern transitions in these samples were observed. Plotting the transition temperatures with the arm number generated a morphology diagram that clearly reflects the effect of macromolecular topology on the crystal pattern formation and selection: Increasing the arm number of the star-shaped PEOs results in a topological change from an “anisotropic line” to an “isotropic sphere”, so the molecular motion also alters from a sliding motion of linear macromolecules to a coordination motion of star-shaped macromolecules. These changes further affect the two key issues of crystal pattern formation: the diffusion and crystallization of macromolecules, so the crystal pattern formation and selection of star-shaped macromolecules depends on their molecular topology.