Grubbs Joe B, Arnold Rachelle M, Roy Anandi, Durie Karson, Bilbrey Jenna A, Gao Jing, Locklin Jason
Department of Chemistry, College of Engineering, and the Center for Nanoscale Science and Engineering, University of Georgia , Athens, Georgia 30602, United States.
Meredian Holdings Group - MHG, 140 Industrial Boulevard, Bainbridge, Georgia 39817, United States.
Langmuir. 2015 Sep 22;31(37):10183-9. doi: 10.1021/acs.langmuir.5b02093. Epub 2015 Sep 4.
Surface-initiated ring-opening polymerization (SI-ROP) of polycaprolactone (PCL) and polylactide (PLA) polymer brushes with controlled degradation rates were prepared on oxide substrates. PCL brushes were polymerized from hydroxyl-terminated monolayers utilizing triazabicyclodecene (TBD) as the polymerization catalyst. A consistent brush thickness of 40 nm could be achieved with a reproducible unique crystalline morphology. The organocatalyzed PCL brushes were chain extended using lactide in the presence of zirconium n-butoxide to successfully grow PCL/PLA block copolymer (PCL-b-PLA) brushes with a final thickness of 55 nm. The degradation properties of "grafted from" PCL brush and the PCL-b-PLA brush were compared to "grafted to" PCL brushes, and we observed that the brush density plays a major role in degradation kinetics. Solutions of methanol/water at pH 14 were used to better solvate the brushes and increase the kinetics of degradation. This framework enables a control of degradation that allows for the precise removal of these coatings.
在氧化物基底上制备了具有可控降解速率的聚己内酯（PCL）和聚丙交酯（PLA）聚合物刷的表面引发开环聚合（SI-ROP）。利用三环癸烯（TBD）作为聚合催化剂，从羟基封端的单分子层聚合PCL刷。可以实现40 nm的一致刷厚，并具有可重复的独特晶体形态。在正丁醇锆存在下，使用丙交酯对有机催化的PCL刷进行扩链，成功生长出最终厚度为55 nm的PCL/PLA嵌段共聚物（PCL-b-PLA）刷。将“接枝自”PCL刷和PCL-b-PLA刷的降解性能与“接枝到”PCL刷进行了比较，我们观察到刷密度在降解动力学中起主要作用。使用pH值为14的甲醇/水溶液更好地溶剂化刷，并提高降解动力学。该框架能够控制降解，从而精确去除这些涂层。
