Synthesis and LCST-type phase separation behavior in organic solvents of poly(vinyl ethers) with pendant imidazolium or pyridinium salts
Synthesis and LCST-type phase separation behavior in organic solvents of poly(vinyl ethers) with pendant imidazolium or pyridinium salts
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DOI：
10.1002/pola.22881
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发表时间：
2008-09-01
影响因子：
--
通讯作者：
Aoshima, Sadahito
中科院分区：
文献类型：
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作者：
Seno, Ken-Ichi;Kanaoka, Shokyoku;Aoshima, Sadahito
含咪唑或吡啶盐侧基的乙烯基醚聚合物在有机介质中发生敏感的低临界溶解温度（LCST）型相分离。用活性阳离子聚合法合成了聚2-氯乙基乙烯基醚，并与相应的咪唑或吡啶反应，定量地得到了结构明确的聚盐。例如，均聚物与丁基咪唑鎓盐的溶液在加热时在氯仿中表现出急剧且可逆的转变。在含有少量良溶剂如1-丁醇（10- 15wt%）的非极性溶剂如甲苯、乙酸乙酯、THF中也观察到灵敏的相分离。证明了盐结构、分子量和浓度对这种行为的依赖性。氢键的断裂是这种相分离的关键因素，如DSC和H-1-NMR测量所示。随着温度的升高，聚合物侧基和溶剂之间的相互作用变弱，因此侧基-侧基相互作用又通过抗衡阴离子诱导。(c)2008 Wiley Periodicals，Inc.
Vinyl ether polymers with imidazolium or pyridinium salt pendants underwent sensitive lower critical solution temperature (LCST)-type phase separation in organic media. Well-defined poly(salts) were quantitatively prepared by reaction with corresponding imidazoles or pyridines and poly(2-chloroethyl vinyl ether), which was synthesized by living cationic polymerization. For example, a solution of the homopolymer with butyl imidazolium salts exhibited a sharp and reversible transition in chloroform upon heating. Sensitive phase separation was also observed in nonpolar solvents, such as toluene, ethyl acetate, THF, containing a small amount of a good solvent, such as 1-butanol (10-15 wt %). The dependency of the salt structures, molecular weight, and the concentration on this behavior was demonstrated. The cleavage of the hydrogen bond is a key factor in this phase separation, as indicated by DSC and H-1-NMR measurements. On increasing the temperature, the interaction between the polymer pendant and the solvent became weaker, hence the pendant-pendant interaction was, in turn, induced through the counter anion. (c) 2008 Wiley Periodicals, Inc.