%0 Journal Article
%T Bulk Polymerization of (L,L)-Lactide Using Non-Organometallic Triazolium Carbene: Limited Advantages
%A O. Coulembier
%A C. Delcourt and Ph. Dubois
%J The Open Macromolecules Journal
%D 2007
%I 
%R 10.2174/1874343900701010001]
%X The ring-opening polymerization (ROP) of L,L-lactide (L-LA) has been studied in bulk using alcohol (either methanol or benzyl alcohol) and 1,3,4-triphenyl-4,5-dihydro-1H-1,2,4-triazol-5-ylidene carbene, 1, respectively as initiator and non-organometallic catalyst, over a range of temperature and alcohol-to-1 molar ratios. Although 1 is known to perfectly control the polymerization of L-LA in solution at 90ˇăC, its efficiency in bulk is drastically decreased since its thermal instability limits the possibility to reach high molecular weight poly(L-lactide) (PL-LA). Under optimum conditions, PL-LA chains with average molecular weight up to 10,000 g.mol-1 have been obtained within 15 minutes and interestingly characterized by very narrow polydispersity indices. Compared to PL-LA conventionally prepared with stannous octoate as catalyst, the thermal stability proved remarkably enhanced when the ROP was promoted by 1.
%U http://www.benthamscience.com/open/tomacroj/articles/V001/1TOMACROJ.htm