US EPA

3163425 

Journal Article 

A Simple and Facile Approach to Aliphatic N-Substituted Functional Eight-Membered Cyclic Carbonates and Their Organocatalytic Polymerization 

Venkataraman, S; Ng, VW; Coady, DJ; Horn, HW; Jones, GO; Fung, TS; Sardon, H; Waymouth, RM; Hedrick, JL; Yang, YY 

2015 

Yes 

Journal of the American Chemical Society
ISSN: 0002-7863
EISSN: 1520-5126 

American Chemical Society 

137 

43 

13851-13860 

English 

26456146 

10.1021/jacs.5b06355 

WOS:000364355900027 

Aliphatic N-substituted functional eight-membered cyclic carbonates were synthesized from N-substituted diethanolamines by intramolecular cyclization. On the basis of the N-substituent, three major subclasses of carbonate monomers were synthesized (N-aryl, N-alkyl and N-carbamate). Organocatalytic ring opening polymerization (ROP) of eight-membered cyclic carbonates was explored as a route to access narrowly dispersed polymers of predictable molecular weights. Polymerization kinetics was highly dependent on the substituent on the nitrogen atom and the catalyst used for the reaction. The use of triazabicyclodecene (TBD), instead of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), as the catalyst for the N-alkyl substituted monomers significantly enhanced the rate of polymerizations. Computational studies were performed to rationalize the observed trends for TBD catalyzed polymerizations. With the optimal organocatalyst all monomers could be polymerized generating well-defined polymers within a timespan of ≤2 h with relatively high monomer conversion (≥80%) and low molar-mass dispersity (Đ(M) ≤ 1.3). Both the glass transition temperatures (T(g)) and onset of degradation temperatures (T(onset)) of these polymers were found to be N-substituent dependent and were in the range of about -45 to 35 °C and 230 to 333 °C, respectively. The copolymerization of the eight membered monomers with 6-membered cyclic comonomers including commercially available l-lactide and trimethylene carbonate produced novel copolymers. The combination of inexpensive starting materials, ease of ring-closure and subsequent polymerization makes this an attractive route to functional polycarbontes. 

Carbonates; Catalysts; Cyclization; Glass transition; Monomers; Organic polymers; Reaction kinetics; Substitution reactions; 1 ,8-diazabicyclo[5.4.0]undec-7-ene; Catalyzed polymerization; Degradation temperatures; Intramolecular cyclizations; Polymerization kinetics; Predictable molecular weight; Rate of polymerization; Trimethylene carbonate; Ring opening polymerization; 1,8 diazabicyclo[5.4.0]undec 7 ene; carbonic acid derivative; copolymer; diethanolamine; monomer; nitrogen; polymer; terpenoid derivative; triazabicyclodecene; trimethylene carbonate; unclassified drug; Article; catalyst; cyclization; glass transition temperature; kinetics; molecular weight; polymerization; ring closing metathesis; ring opening metathesis polymerization; synthesis; temperature