The effect of grafting density and side chain length on the conformation of PEG grafted bottlebrush polymers

摘要

PEG grafted polymers are a kind of promising materials, and widely applied in polymer electrolytes, lubricants, biotechnology and biomedical science. While up to now, systematical researches of the relationship between architecture and conformation of PEG grafted polymers are very rare. Here, we efficiently and successfully prepared a series of PEG grafted polymers with different grafting density, and side chain length by combining ring-opening metathesis polymerization (ROMP) and Copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction, and then characterized the conformations of the synthesized bottlebrush polymers by AFM technique. The AFM images showed that all the polymers P(NB-alkyne)(400)-g-PEG with low grafting density were spherical morphology, while the polymers P(NB-2alkyne)(400)-g-PEG and P(NB-4alkyne)(394)-g-PEG presented cylindrical morphology, which indicated that only grafting density could determine the shape of the prepared PNB-g-PEG bottlebrush polymers. While, the side chain length could affect the size of prepared PEG grafted bottlebrush polymers.