ABA Triblock Copolymers Based on Linear Poly(oxymethylene) and Hyperbranched Poly(glycerol): Combining Polyacetals and Polyethers

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• 作者：Rebecca Klein ; Christoph Sch眉ll ; Elena Berger-Nicoletti ; Michael Haubs ; Klaus Kurz ; Holger Frey
• 刊名：Macromolecules
• 出版年：2013
• 出版时间：November 26, 2013
• 年：2013
• 卷：46
• 期：22
• 页码：8845-8852
• 全文大小：379K
• 年卷期：v.46,no.22(November 26, 2013)
• ISSN：1520-5835

文摘

The synthesis of hyperbranched-linear-hyperbranched ABA triblock copolymers based on a linear poly(oxymethylene) (POM) block and hyperbranched poly(glycerol) (hbPG) blocks is described. The polymers containing a polyacetal polyether structure were prepared from linear bishydroxy-functional POM macroinitiators, obtained by cationic ring-opening polymerization of trioxane and 1,3-dioxolane as a comonomer with formic acid as a transfer agent and subsequent hydrolysis of the formate group. Partial deprotonation of the resulting hydroxyl groups permitted 鈥渉ypergrafting鈥?of glycidol by anionic ring-opening multibranching polymerization (ROMBP). With respect to the hyperbranched blocks, the obtained polymers show the expected, moderate molecular weight distributions in the range of 1.31 to 2.01 and molecular weights between 6100 and 22900 g mol^鈥?. Both the degree of polymerization of the linear POM segments as well as the molecular weight of the hbPG blocks have been varied. Key properties, such as thermal behavior and thermal stability, degree of crystallization and surface properties were investigated, showing an adjustable degree of crystallization and enhanced hydrophilicity depending on the hbPG content.