| Summary: | 碩士 === 國立清華大學 === 化學系 === 103 === We demonstrated one-pot synthesis of polystyrene-b-polycaprolactone (PSt-b-PCL) mediated by Cp2TiCl2. First we optimized styrene radical polymerization mediated by Cp2TiCl2 and tuned many factors of polymerization such as benzaldehyde, Cp¬2TiCl2, nano-sized zinc. We observed lower concentration benzaldehyde led to better polymerization control, nano-sized zinc not only acted a role of reducing agent, but had relationship with polymerization control, more Cp¬2TiCl2 afforded lower polymer molecule weight. Based on optimized styrene polymerization, we successfully synthesized blockcopolymer of styrene (St) and-caprolactone (CL). According the GPC results, the polymerization was initiated with good living characteristics demonstrated by linear increasing in molecular weight with time. In second part, we used cyclic voltammetry (CV) and polymerization results to discuss the relationship between redox ability of various cobalt complexes (CoII(TMP), CoII(acac)2, CoII(etsalen), CoII(etsalentBu), CoII(Salen*) and CoII (Salophen)) and cobalt-mediated radical polymerization (CMRP) of methyacrylate MA. We found CoII(Salophen) had low redox ability and also proivded worse MA polymerization, in addition, CoII(TMP) had high redox ability and showed better polymerization. It seems that cobalt complexes having high redox bility can afford better MA polymerization.
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