Synthesis of ethylene/vinyl ester copolymers with pendent linear branches via ring-opening metathesis polymerization of fatty acid-derived cyclooctenes

Abstract

Fatty acid-derived cyclooctenes, including n-hexanoic acid (M1), n-octanoic acid (M2), lauric acid (M3), and palmitic acid (M4), were prepared as monomers and polymerized by ring-opening metathesis polymerization (ROMP) using Grubbs second-generation catalyst (G2). In all the cases, the regio-irregular unsaturated polymers with pendent linear branches were obtained, which could be saturated by chemical hydrogenation with TSH/TPA in high conversion, yielding ethylene/vinyl ester copolymers with pendent linear branches on precisely every eighth backbone carbon. Both unsaturated and saturated polymers were amorphous, and their structures were characterized by FTIR, 1H and 13C NMR spectra, and elemental analysis. Differential scanning calorimetry (DSC) and thermo-gravimetric analysis (TGA) were used to study their thermal properties. The chain length of branches greatly affected the thermal properties of polymers. After hydrogenation, the thermal degradation stability of polymers was relatively improved. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 2211–2220