Synthesis Modeling And Characterization Of Ethylene Oxide Segmented Microblock Copolymers

Author : Yi Wang (Polymer engineer)
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (134 download)

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Download or read book The Synthesis and Characterization of Amphiphilic Poly(ethylene Oxide)-block-poly(octadecyl Acrylate) Block Copolymers written by Yi Wang (Polymer engineer) and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A series of well-defined poly(ethylene oxide)-block-poly(octadecyl acrylate) (PEO-b-PODA) diblock copolymers were successfully synthesized by reversible addition fragmentation transfer (RAFT) polymerization with low polydispersities (M[subscript w]/M[subscript n] = 1.09-1.13). The crystallization behavior of poly(ethylene oxide)-block-poly(octadecyl acrylate) (PEO-b-PODA) diblock copolymers has been studied by differential scanning calorimetry (DSC), small-angle X-ray scattering (SAXS) and polarized optical microscopy (POM). The melt morphology of PEO455-PODA19 experienced a transition from lamella to cylinder at 130°C. For the double crystalline block copolymer PEO455-PODA19, the micro-phase separation at 55°C created lamellar micro-domains, which confined the PEO blocks as it crystallized. The leading crystallization of PEO blocks then created a space that confined PODA crystallites as they are developed. The spherulites were formed first when PEO started to crystallize, but crystallites with polyhedral shape finally formed. As for the micelle behavior, the transmission electron microscopy (TEM) showed that amphiphilic block copolymers PEO-PODA with different volume fractions of hydrophobic PODA blocks ranging from 21% to 54%, were able to self-assemble in water forming spherical micelles.