Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, USA.
Macromol Rapid Commun. 2011 Jan 3;32(1):74-81. doi: 10.1002/marc.201000477. Epub 2010 Oct 13.
Amphiphilic star shaped polymers with poly(ethylene oxide) (PEO) arms and cross-linked hydrophobic core were synthesized in water via either conventional free radical polymerization (FRP) or atom transfer radical polymerization (ATRP) techniques using a simple "arm-first" method. In FRP, PEO based macromonomers (MM) were used as arm precursors, which were then cross-linked by divinylbenzene (DVB) using 2,2'-azoisobutyronitrile (AIBN). Uniform star polymers (Mw/Mn < 1.2) were achieved through adjustment of the ratio of PEO MM, DVB, and AIBN. While in case of ATRP, both PEO MM, and PEO based macroinitiator (MI) were used as arm precursors with ethylene glycol diacrylate as cross-linker. Even more uniform star polymers with less contamination by low MW polymers were obtained, as compared to the products synthesized by FRP.
具有聚氧乙烯（PEO）臂和交联疏水性核的两亲性星形聚合物通过常规自由基聚合（FRP）或原子转移自由基聚合（ATRP）技术在水中合成，使用简单的“臂先”方法。在 FRP 中，使用基于 PEO 的大分子单体（MM）作为臂前体，然后用二乙烯基苯（DVB）和 2,2'-偶氮二异丁腈（AIBN）交联。通过调整 PEO MM、DVB 和 AIBN 的比例，可以实现均匀的星形聚合物（Mw/Mn <1.2）。而在 ATRP 的情况下，PEO MM 和基于 PEO 的大分子引发剂（MI）都被用作臂前体，乙二醇二丙烯酸酯作为交联剂。与 FRP 合成的产物相比，得到了更均匀的星形聚合物，并且低 MW 聚合物的污染更少。
