Thermo-responsive diblock copolymers of Poly(N-isopropylacrylamide) and Poly(N-vinyl-2-pyrroridone) synthesized via organotellurium-mediated controlled radical polymerization (TERP)
Thermo-responsive diblock copolymers of Poly(N-isopropylacrylamide) and Poly(N-vinyl-2-pyrroridone) synthesized via organotellurium-mediated controlled radical polymerization (TERP)
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DOI：
10.1021/ma070769x
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发表时间：
2007-07
期刊：
影响因子：
5.5
通讯作者：
S. Yusa;S. Yamago;M. Sugahara;Sanae Morikawa;Tohei Yamamoto;Y. Morishima
中科院分区：
文献类型：
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作者：
S. Yusa;S. Yamago;M. Sugahara;Sanae Morikawa;Tohei Yamamoto;Y. Morishima
聚二嵌段共聚物（N-异丙基丙烯酰胺）（PNIPAM）和聚N-乙烯基吡咯烷酮（PNVP）基于有机碲介导的可控自由基聚合（TERP）对N-乙烯基-2-吡咯烷酮均聚反应的控制优于黄原酸酯交换设计的大分子结构（MADIX）的发现，TERP导致PNVP的分子量分布更窄。采用1H NMR、浊度、准弹性光散射（QELS）和静态光散射（SLS）等技术对3种不同嵌段长度的嵌段共聚物PNIPAM 110-b-PNVP 53、PNIPAM 110-b-PNVP 234和PNIPAM 76-b-PNVP 219在水中的热诱导缔合性能进行了表征。当溶液温度低于聚集温度（Ta）时，所有三种嵌段共聚物都以分子形式（作为单聚体状态）溶解在水中，所述聚集温度（Ta）接近PNIPAM嵌段的下临界溶液温度（LCST）。
Diblock copolymers of poly(N-isopropylacrylamide) (PNIPAM) and poly(N-vinyl-2-pyrrolidone) (PNVP) (PNIPAMm-b-PNVPn) with well-defined block lengths were successfully synthesized by organotellurium-mediated controlled radical polymerization (TERP) based on the finding that the homopolymerization of N-vinyl-2-pyrrolidone was better-controlled by TERP than by macromolecular architecture designed by interchange of xanthates (MADIX), TERP resulting in a narrower molecular weight distribution of PNVP. Heat-induced association properties in water of three block copolymers with different block lengths, PNIPAM110-b-PNVP53, PNIPAM110-b-PNVP234, and PNIPAM76-b-PNVP219, were characterized by 1H NMR, turbidity, quasi-elastic light scattering (QELS), and static light scattering (SLS) techniques. All three block copolymers dissolve in water molecularly (as a unimer state) when the solution temperature is below an aggregation temperature (Ta) that is near a lower critical solution temperature (LCST) for the PNIPAM block....