文摘
Dumbbell-shaped triblock molecular brushes were synthesized by ring-opening metathesis polymerization (ROMP) of poly(lactide) macromonomers with terminal norbornene groups (NB-PLA) in a sequential addition manner. By changing the macromonomer size and the feed ratio of Grubbs鈥?catalyst to macromonomer, the dimensions of the 鈥渂all鈥?and 鈥渂ar鈥?of the dumbbell-shaped molecular brushes were controlled. The growth and production of well-defined structures were verified by gel permeation chromatography (GPC), and the final dumbbell-shaped architectures were visualized by atomic force microscopy (AFM). This synthetic methodology represents a rapid and convenient route to unique macromolecular topologies.