Introduction of Azobenzenes or Vinyl Groups into Ends of Rodlike Polymers
Introduction of Azobenzenes or Vinyl Groups into Ends of Rodlike Polymers
复制标题
将偶氮苯或乙烯基引入棒状聚合物的末端
DOI：
10.1021/ma030166v
复制
发表时间：
2003
期刊：
影响因子：
5.5
通讯作者：
M. Donkai
中科院分区：
文献类型：
--
作者：
K. Se;Kouji Aoyama;Junya Aoyama;M. Donkai
大分子可以具有一些简单的形状，如线圈、球体和棒状，也可以具有一些简单的结构，如柔性聚合物、星形聚合物、1,2超支化聚合物、3环聚合物和棒状聚合物。在形状和建筑类别中，棒状聚合物的特点是高度不对称。由于这种不对称的形状特征，棒状聚合物表现出一些独特的物理性质，如液晶性、各向异性溶液、介电和流变行为。7,8因此，棒状聚合物可以应用于新的聚合物器件。9-12然而，棒状聚合物的自扩散系数是链动力学中的基本分子参数，无法通过强制瑞利散射技术确定，尽管柔性聚合物（如聚苯乙烯）的自扩散系数已经报道了超过15年。在合成具有理想分子量和窄分子量分布（MWDs）的染料标记棒状聚合物的尝试中出现了困难。棒状聚合物的代表之一是聚（正己基异氰酸酯）。Novac等人已经报道了活性钛催化异氰酸酯配位聚合。他们制备了定义明确的多异氰酸酯（PICs）和由两种不同的PIC嵌段共聚物组成的嵌段共聚物。为了稳定合成的PIC， Novac等人使用乙酸酐衍生物对聚合进行端封，而Hatada等人则使用乙酰氯衍生物。17然而，在Novac和Hatada报道了PIC的末端封顶后，尚未研究活端与其他官能团的反应。因此，本研究处理了这种偶联反应，将染料化合物引入到活的菲氏体的末端，以便在强制瑞利散射实验中使用合成的染料标记菲氏体。也可以使用相同的合成路线制备菲式大单体，这与Novac等人报道的早期研究不同。18当菲式大单体聚合时，星形聚合物具有棒-
Macromolecules can take on some simple shapes, such as coils, spheres, and rods, as well as some simple architectures, such as flexible polymers, star-shaped polymers, 1, 2 hyperbranched polymers, 3 ring polymers, and rodlike polymers. In both the shape and architectural categories, the rodlike polymers are characterized by high asymmetry. 4 Because of this asymmetric shape characteristic, the rodlike polymers have shown some unique physical properties such as liquid crystallinity, 5 anisotropic solution, 6 and dielectric and rheological behaviors. 7, 8 Thus, rodlike polymers might be applied to new polymeric devices. 9-12 However, the self-diffusion coefficients of rodlike polymers, which are fundamental molecular parameters in chain dynamics, could not be determined by a forced Rayleigh scattering technique, although those coefficients of flexible polymers, such as polystyrene, have been reported for more than 15 years. 13 The difficulty arose in the attempt to synthesize dye-labeled rodlike polymers having desired molecular weights and narrow molecular weight distributions (MWDs).One of the representatives of the rodlike polymers is poly (n-hexyl isocyanate)(PHIC). Living titaniumcatalyzed coordination polymerization of isocyanates has been reported by Novac et al. 14, 15 They prepared welldefined polyisocyanates (PICs) and block copolymers consisting of two different PIC blocks. To stabilize the resultant PIC, Novac et al. end-capped the polymerization using acetic anhydride derivatives, 16 and Hatada et al. did so by using acetyl chloride derivatives. 17 However, after Novac and Hatada reported the endcapping of PIC, the reaction of the living ends with other functional groups has not been studied. Therefore, the present study deals with this coupling reaction, introducing dye compounds into an end of living PHIC in order to employ the resultant dye-labeled PHIC in a forced Rayleigh scattering experiment. PHIC macromonomers might also be prepared using the same synthetic route, which is different from that of an earlier study reported by Novac et al. 18 When PHIC macromonomers are polymerized, star polymers having rod-