Cross‐metathesis of biorenewable dioxalates and diols to film‐forming degradable polyoxalates. Issue 14 (11th May 2018)

• Record Type: Journal Article
• Authors: Rajput, Bhausaheb S.; Ram, Farsa; Menon, Shamal K.; Shanmuganathan, Kadhiravan; Chikkali, Samir H.
• Is Part Of: Journal of polymer science. Volume 56:Issue 14(2018)
• Page Start: 1584
• Page End: 1592
• Publication Date: 2018-05-11
• Subjects: cross‐metathesis -- polyoxalates -- renewable films -- renewable resources -- sustainable chemistry; 547
• DOI: 10.1002/pola.29043
• Languages: English
• ISSNs: 0887-624X

Abstract

ABSTRACT: Starting from commonly available sugar derivatives, a single step protocol to access a small family of isohexide‐dioxalates (2a–c ) has been established. The synthetic competence of2a–c has been demonstrated by subjecting them to condensation polymerization. Quite surprisingly, the proton NMR of poly(isomannide‐co‐hexane)oxalate revealed a 1:2 ratio between isomannide‐dioxalate (2a ) and 1, 6‐hexanediol (3a ) in the polymer backbone. This intriguing reactivity was found to be an outcome of a cross metathesis reaction between2a and3a . The cross metathesis products3a "[2‐(2‐methoxyacetoxy)ethyl 2‐(2‐hydroxyethoxy)‐2‐(λ3‐oxydanylidene)acetate] and2a '(3R, 6R)‐6‐hydroxyhexahydrofuro[3, 2‐b]‐furan‐3‐yl methyl oxalate were isolated in a control experiment. Based on direct and indirect evidence, and control experiments, an alternative polymerization mechanism is proposed. Polymerization conditions were optimized to obtain polyoxalatesP1(2a‐3a)‐P9(2c‐3c) with molecular weights in the range of 14, 000–68, 000 g/mol, and narrow polydispersities. The identity of the polyoxalates was unambiguously established using 1‐2D NMR spectroscopy, MALDI‐ToF‐MS, and GPC measurements. The practical implication of these polymers is demonstrated by preparing transparent, mechanically robust films. The environmental footprint of the selected polyoxalates was investigated by subjecting them to solution and solid‐state degradation. The polyoxalates were found to be amenable to degradation. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem.2018, 56, 1584–1592 Abstract : A single step synthetic protocol to access a small family of sugar derived‐dioxalates and their polymerization to renewable, high molecular weight, film forming, degradable polyoxalates has been established. The intriguing reactivity is an outcome of a cross metathesis reaction between the two monomers. Based on direct and indirect evidence and control experiments, an alternative polymerization mechanism is proposed.