| Summary: | 博士 === 國立交通大學 === 應用化學系所 === 97 === Most of today’s materials require additional processing or modification steps in order to obtain the properties that make suitable for particular applications. As an alternative to these raditional fabrication pathways, routes that use the self-assembly of polymeric building blocks are attracting increasing attention. In other words, the self-assembly of block copolymer systems has been extensively studied.
In this thesis, we have synthesized series of poly(vinylphenol-b-methyl methacrylate) (PVPh-b-PMMA) diblock copolymers through an anionic polymerization and a subsequent selective hydrolysis reaction and investigated a new type of A-B/C blend formed between poly(vinylphenol-b-methyl methacrylate) and poly(vinylpyrrolidone) which displays unusual phase behavior. DSC results demonstrate that the miscible PVPh-b-PMMA copolymer becomes immiscible up on blending with 20-60 wt % PVP due to two Tgs existed in the blend. Results from TEM images and SAXS analysis indicate that different compositions of PVPh-b-PMMA/PVP blends induce different microphase separation structures due to the significantly stronger hydrogen bond interaction between PVPh and PVP than that between PVPh and PMMA which has confirmed by FT-IR analyses.
A series of immiscible crystalline-amorphous diblock copolymers, poly(ε-caprolactone-b-4-vinyl pyridine) (PCL-b-P4VP), were synthesized through combination of sequential ring-opening and controlled living free radical (nitroxide-mediated) polymerizations and then blended with poly(vinyl phenol) (PVPh) homopolymer. Self-assembly morphologies of these immiscible PCL-b-P4VP diblock copolymers changing through competitive hydrogen-bonding interactions with the increase of PVPh contents are presented by TEM images and SAXS analyses. DSC, WAXD, and FT-IR techniques are used to investigate the hydrogen-bonding interactions in this system. Furthermore, we have also employed a PCL-b-P4VP copolymer with a low molecular weight of P4VP to investigate the difference of the miscibility, the phase behavior, and the hydrogen-bonding interaction mechanism compared PCL-b-P4VP/PVPh with PCL-b-P4VP/PVPh-b-PS blend system. All results confirm that the icompatibility of the added PS block with the other three blocks is the main reason which induces the difference of the microphase-separation between PCL-b-P4VP/PVPh and PCL-b-P4VP/PVPh-b-PS blend system.
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