Commarieu Basile, Potier Jonathan, Compaore Moubarak, de Boever Raphael, Imbeault Regis, Claverie Jerome P
Department of Chemistry, Université de Sherbrooke.
Department of Chemistry, Université de Sherbrooke;
J Vis Exp. 2017 Feb 27(120):54552. doi: 10.3791/54552.
Norbornene can be polymerized by a variety of mechanisms, including insertion polymerization whereby the double bond is polymerized and the bicyclic nature of the monomer is conserved. The resulting polymer, polynorbornene, has a very high glass transition temperature, Tg, and interesting optical and electrical properties. However, the polymerization of functional norbornenes by this mechanism is complicated by the fact that the endo substituted norbornene monomer has, in general, a very low reactivity. Furthermore, the separation of the endo substituted monomer from the exo monomer is a tedious task. Here, we present a simple protocol for the polymerization of substituted norbornenes (endo:exo ca. 80:20) bearing either a carboxylic acid or a pendant double bond. The process does not require that both isomers be separated, and proceeds with low catalyst loadings (0.01 to 0.02 mol%). The polymer bearing pendant double bonds can be further transformed in high yield, to afford a polymer bearing pendant epoxy groups. These simple procedures can be applied to prepare polynorbornenes with a variety of functional groups, such as esters, alcohols, imides, double bonds, carboxylic acids, bromo-alkyls, aldehydes and anhydrides.
降冰片烯可通过多种机理进行聚合，包括插入聚合，即双键发生聚合且单体的双环结构得以保留。所得聚合物聚降冰片烯具有非常高的玻璃化转变温度Tg以及有趣的光学和电学性质。然而，通过这种机理对功能性降冰片烯进行聚合会因以下事实而变得复杂：内型取代的降冰片烯单体通常具有非常低的反应活性。此外，将内型取代的单体与外型单体分离是一项繁琐的任务。在此，我们提出了一种简单的方法，用于聚合带有羧酸或侧链双键的取代降冰片烯（内型:外型约为80:20）。该过程不需要分离两种异构体，并且在低催化剂负载量（0.01至0.02 mol%）下即可进行。带有侧链双键的聚合物可以高产率进一步转化，以得到带有侧链环氧基团的聚合物。这些简单的方法可用于制备具有各种官能团的聚降冰片烯，如酯、醇、酰亚胺、双键、羧酸、溴代烷基、醛和酸酐。
