Ring-Closing Depolymerization: A Powerful Tool for Synthesizing the Allyloxy-Functionalized Six-Membered Aliphatic Carbonate Monomer 2-Allyloxymethyl-2-ethyltrimethylene Carbonate
2014 (English)In: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 47, no 18, 6189-6195 p.Article in journal (Refereed) Published
Ring-dosing depolymerization is demonstrated to be a powerful synthetic methodology for the formation of six-membered functional aliphatic carbonate monomers, providing a rapid, straightforward, inexpensive, and green route for obtaining six-membered functional aliphatic carbonate monomers at a scale greater than 100g. The utility of this technique was observed via the synthesis of the allyloxy-functionalized six-membered cyclic carbonate monomer 2-allyloxymethyl-2-ethyltrimethylene carbonate (AOMEC). The synthesis was performed in a one-pot bulk reaction, starting from trimethylolpropane allyl ether, diethyl carbonate, and NaH, resulting in a final AOMEC yield of 63%. The synthetic methodology is based upon the reversible nature of this class of polymers. The anionic environment produced by NaH was observed to mediate the monomer equilibrium concentration; thus, an additional catalyst is not required to induce depolymerization. 1,5,7-Triazabicyclo[4.4.0]dec-5-ene (TBD) was demonstrated to be a very active catalyst for the ring-opening polymerization (ROP) of AOMEC, resulting in a rapid (k(p)(aPP) =28.2 s(-1)) and controlled polymerization with a low dispersity D = 1.2). The availability and activity of the functionality of poly(AOMEC)s were established through subsequent postpolymerization functionalization via the UV-initiated thiol-ene chemistry of poly(AOMEC) with 1-dodecanethiol and benzophenone as a radical initiator. The functionalization proceeded with high control and with a linear relation between the molecular weight and conversion of the unsaturation, revealing the high orthogonality of the reaction and the stability of the carbonate backbone. Hence, as a synthetic methodology, depolymerization provides a straightforward and simple approach for the synthesis of the highly versatile functional carbonate AOMEC. In addition, formation of the monomer does not require any solvents, reactive ring-dosing reagents, or transition-metal-based depolymerization catalysts, thereby providing a "greener" route for obtaining functional carbonate monomers and polymers.
Place, publisher, year, edition, pages
2014. Vol. 47, no 18, 6189-6195 p.
Opening Polymerization, Cyclic Carbonates, 2, 2-Dimethyltrimethylene Carbonate, Efficient Synthesis, Organic Carbonates, Copolymers, Esters, Polycarbonates, Mechanism, Polymers
IdentifiersURN: urn:nbn:se:kth:diva-154373DOI: 10.1021/ma5012304ISI: 000342184700006ScopusID: 2-s2.0-84918537979OAI: oai:DiVA.org:kth-154373DiVA: diva2:757108
FunderEU, European Research Council, 246776
QC 201410212014-10-212014-10-202015-05-22Bibliographically approved