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With the increased awareness of avoiding residue metals, the field of organocatalysts is attracting more attention. Aliphatic tertiary amines, such as triethylamine (TEA), N , N , N , N ‐tetramethylethylenediamine (TMEDA) and 1,1,4,7,7‐pentamethyldiethylenetriamine (PMDTA), have low boiling points which allow their easy elimination after a chemical reaction. Here, we used these aliphatic tertiary amines to catalyze ring‐opening polymerizations (ROPs) of trimethylene carbonate (TMC). In the presence of benzyl alcohol, the catalytic activities of the tertiary amines were in the order of TEA < TMEDA < PMDTA. Correlation between the molecular weight of polycarbonates and monomer conversions was linear, suggesting the polymerization was controlled. The polymerization pathway was presumed to follow an alcohol‐activated mechanism according to the end‐group fidelity determined using 1 H NMR spectroscopy. The ROP of TMC was also successfully initiated by PEO 99 ‐PPO 65 ‐PEO 99 (F127) under the catalysis of the tertiary amines, producing well‐defined PTMC n ‐F127‐PTMC n copolymers with narrow dispersity ( ca 1.2) and with thermosensitive properties in aqueous solution. Furthermore, copolymerizations of TMC with acryloyl‐containing cyclic carbonate were catalyzed by the tertiary amines in the presence of F127. No crosslinking reactions were detected. Our results demonstrate that the aliphatic tertiary amines have the potential to catalyze TMC homo‐ or copolymerization featuring controllable structure and composition under mild conditions.
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Yan et al. (2012) studied this question.
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