Henke Helena, Wilfert Sandra, Iturmendi Aitziber, Brüggemann Oliver, Teasdale Ian
Institute of Polymer Chemistry, Johannes Kepler University Linz, 4060, Leonding, Austria.
J Polym Sci A Polym Chem. 2013 Oct 1;51(20):4467-4473. doi: 10.1002/pola.26865.
Using living cationic polymerization, a series of polyphosphazenes is prepared with precisely controlled molecular weights and narrow polydispersities. As well as varying chain length through the use of a living polymerization, amine-capped polyalkylene oxide (Jeffamine) side chains with varied lengths are grafted to the polymer backbone to give a series of polymers with varied dimensions. Dynamic light scattering and size exclusion chromatography are used to confirm the preparation of polymers with a variety of controlled dimensions and thus hydrodynamic volumes. Furthermore, it is demonstrated how the number of arms per repeat unit, and thus the density of branching, can also be further increased from two to four through using a one-pot thiolactone conversion of the Jeffamines, followed by thiol-yne addition to the polyphosphazene backbone. These densely branched, molecular brush-type polymers on a biodegradable polyphosphazene backbone all show excellent aqueous solubility and have potential in drug-delivery applications.
通过活性阳离子聚合反应，制备了一系列具有精确控制分子量和窄多分散性的聚磷腈。除了通过活性聚合反应改变链长外，还将不同长度的胺封端聚环氧烷（Jeffamine）侧链接枝到聚合物主链上，得到一系列具有不同尺寸的聚合物。利用动态光散射和尺寸排阻色谱法来确认制备出了具有各种可控尺寸以及流体力学体积的聚合物。此外，还展示了如何通过对Jeffamines进行一锅法硫内酯转化，然后将硫醇-炔加成到聚磷腈主链上，使每个重复单元的臂数，进而使支化密度从两个进一步增加到四个。这些以可生物降解的聚磷腈为主链的密集支化分子刷型聚合物均表现出优异的水溶性，并在药物递送应用中具有潜力。
