Multi-POSS Cluster-Wrapped Polymers and Their Block Copolymers with A PEO Bottlebrush Polymer: Synthesis and Aggregation
Multi-POSS Cluster-Wrapped Polymers and Their Block Copolymers with A PEO Bottlebrush Polymer: Synthesis and Aggregation
复制标题
多POSS簇包裹聚合物及其嵌段共聚物与PEO洗瓶刷聚合物：合成和聚集
作者：
孟垂松;颜雨坤;王维
本文报道了一种通过活性开环易位聚合合成多簇包裹聚合物及其嵌段共聚物的方法，该方法采用具有可控链长和组成的瓶刷聚合物。为了在聚合物主链上包裹多个团簇，首先将2 ~ 4个多面体低聚倍半硅氧烷（POSS）团簇置于低代单枝晶的外围，形成团簇-单枝晶。然后，合成了含有簇-树枝基元和一个簇的双烯单体。最后，这些单体的聚合进行了使用Grubbs催化剂在温和的条件下，生成多POSS簇包裹的聚合物。同时，还制备了它们与含有聚环氧乙烷的瓶刷聚合物的嵌段共聚物。聚合物和嵌段共聚物的绝对分子量和相对分子量均使用尺寸排阻色谱法与在线光散射和折射率检测器测定。我们的分子量的分析表明，绝对和相对分子量之间的差异增加时，POSS数在侧部分从1增加到4。因此，通过溶液自组装形成的嵌段共聚物的胶束的尺寸随着POSS数的增加而增加，这是由于聚合物链的拉伸。
In this paper, we report an approach for synthesizing multi-cluster-wrapped polymers and their block copolymers with a bottlebrush polymer with controlled chain length and composition via living ring-opening metathesis polymerization. To wrap more than one cluster on a polymer backbone, two to four polyhedral oligomeric silsesquioxane (POSS) clusters were firstly placed at the periphery of low-generation monodendrons to generate cluster-dendrons. Then, norbornene monomers that contain the cluster-dendrons and also one cluster were synthesized. Finally, the polymerization of these monomers was carried out using a Grubbs catalyst under mild conditions to generate multi-POSS cluster-wrapped polymers. Meanwhile, their block copolymers with a bottlebrush polymer that contains a polyethylene oxide were also prepared. Both the absolute and relative molecular weights of the polymers and block copolymers were determined using size-exclusion chromatography with both on-line light-scattering and refractive index detectors. Our analysis of their molecular weights indicates that the differences between absolute and relative molecular weights increase when the POSS number in the side moieties increases from 1 to 4. Thus the size of the micelles of the block copolymers formed via solution self-assembly increases with increasing POSS number due to the stretching of the polymer chains.