A New Strategy To Access Polymers with Aggregation-Induced Emission Characteristics
writer：Wei Zhao,? Chuanyang Li, Bo Liu, Xue Wang, Ping Li, Yang Wang, Chunji Wu, Changguang Yao, Tao Tang,
keywords：biocompatible polyesters; cyclic esters; chain transfer agent; in situ; immortal ring-opening polymerizations
source：期刊
specific source：http://pubs.acs.org/doi/pdf/10.1021/ma500985j
Issue time：2014年
A highly efficient
strategy for synthesizing the first biocompatible polyesters with AIE
characteristics has been established via immortal ring-opening polymerizations
of cyclic esters bearing nonluminophores. In the process, the large excess
hydroxyl-modified AIE active compound, acting as the chain transfer agent,
attaches to the active rare-earth metal catalyst via the rapid-reversible
exchange reaction to initiate the polymerization. Thus, more polyester chains
appear to grow from one active metal species, and the AIE fragments are
incorporated into the polymer chains at specific sites, in situ.
The resultant polyesters have linear, block, or star-shaped microstructures
mimicking those of the modified AIE compounds. The polymerization solutions can
be directly fabricated to large-area thin solid films. The obtained PLA, for
instance, emits fluorescence in water/THF mixtures owing to aggregation, the
intensity of which is 2850-fold stronger than that in THF solution. This
strategy avoids complicated preparation of AIE-active monomers and/or usage of
toxic metal reagents for catalyzing the coupling reactions in order to
introduce AIE-active fragments, which provides a straightforward approach to
access AIE active or other functional polymers from hardly modified monomers.
