Benzyl-PEG11-t-butyl acetate is a functionalized polyethylene glycol derivative. Its structure features benzyl as the terminal group, with 11 ethylene glycol units (PEG11) in the middle, and t-butyl acetate as the end-capping group. The production process typically involves step-growth polymerization, where the degree of polymerization of the ethylene glycol segments is precisely controlled, and benzyl and t-butyl ester protecting groups are introduced to enhance stability. This product is widely used in polymer material modification, drug delivery systems, and bioconjugation fields. Its flexible PEG segment improves material wettability, while the t-butyl ester group provides reversible protection, facilitating subsequent functionalization modifications. It serves as a key intermediate for synthesizing complex molecular probes and targeted carriers.