Yamauchi Yoshihiro, Horimoto Noriko Nishizawa, Yamada Kuniyo, Matsushita Yoshitaka, Takeuchi Masayuki, Ishida Yasuhiro
National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba, 305-0047, Japan.
RIKEN Center for Emergent Matter Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.
Angew Chem Int Ed Engl. 2021 Jan 18;60(3):1528-1534. doi: 10.1002/anie.202009759. Epub 2020 Nov 30.
The longest bottlebrush polymers reported so far (up to 7 μm in length) were synthesized in two steps from a norbornene derivative bearing two 2-bromoisobutylate moieties (NB). The key to this achievement is the excellent reactivity of NB in ring opening metathesis polymerization, which proceeded in a well-controlled manner with quantitative conversion of NB for monomer-initiator ratios ranging up to 10,000. The resultant polymer derived from NB was readily converted to various bottlebrush polymers in a divergent synthetic route by grafting vinyl monomers from the 2-bromoisobutylate units in NB via atom transfer radical polymerization. The structure of the ultra-long bottlebrush polymer was directly observed using atomic force microscopy.
目前报道的最长的刷状聚合物（长度可达7 μm）是由带有两个2-溴异丁酸酯基团的降冰片烯衍生物（NB）分两步合成的。这一成果的关键在于NB在开环易位聚合反应中的优异反应活性，对于高达10,000的单体-引发剂比例，该反应能以良好的可控方式进行，NB的转化率达到定量。通过原子转移自由基聚合从NB中的2-溴异丁酸酯单元接枝乙烯基单体，经由发散合成路线，由NB衍生得到的聚合物很容易转化为各种刷状聚合物。使用原子力显微镜直接观察了超长刷状聚合物的结构。
