Poly[ethylene‐co‐(vinyl alcohol)]‐graft‐poly(ε‐caprolactone) Synthesis by Reactive Extrusion, 1 ‐ Structural and Kinetic Study

Abstract

Chemical modification of EVOH in the molten state at 185 °C by a grafting from process of poly(ε‐caprolactone) in batch was studied. 1H NMR was used to characterize the structure evolutions of PCL grafts. In addition to grafting reactions, dynamic covalent transesterification reactions between EVOH residual alcohols and the polyester grafts led to a redistribution of the PCL grafts length. $\mathop {\overline {Dp} }\nolimits_n $ up to 27 and SR up to 80% were obtained. Experiments made in a corotating mini twin‐screw extruder also confirmed these results. The effect of the alcohol to caprolactone ratio and catalyst concentration (SnOct2) on kinetic evolution showed that few minutes were necessary to complete the polymerization. A kinetic model was proposed and adequate conditions for the synthesis by reactive extrusion were defined.magnified image

Improving the Barrier Properties of Poly(Lactic Acid) by Blending with Poly(Ethylene-Co-Vinyl Alcohol)

“…According to the mechanism we proposed in Scheme 1, the EVOH-g-PLA copolymer should be generated during processing. Becquart, et al [27] synthesized a similar graft copolymer, EVOH-g-poly(ε-caprolactone) (PCL), by reactive extrusion. The signals corresponding to the methine protons of EVOH, which were linked Downloaded by [Selcuk Universitesi] at 14:56 03 January 2015 Scheme 1.…”

Solvent-free preparation, characterization, and properties of SEBS–g–polycarbonate copolymers

“…[5] The first one is the addition of a graft or block copolymer. [6][7][8][9][10][11][12] To form a graft copolymer, two strategies exist, the grafting from between polymers [13][14][15][16][17][18][19][20][21] and the grafting onto, [22][23][24][25][26][27][28][29] with a polymer bearing an initiating function previously induced by ozonolysis or irradiation. [30,31] A coupling reaction through a function can also be used to generate specific functions onto a polymer chain moiety to then start a grafting from or a grafting onto.…”

Effect of Compatibilization on Poly-ε-Caprolactone Grafting onto Poly(ethylene-co-vinyl alcohol)

“…EVOH is a non-biodegradable copolymer while PCL is biodegradable polyester. Grafting PCL on EVOH or other non-biodegradable polymers associates mechanical properties of a non-biodegradable backbone to the biodegradability of grafts [10][11][12][13][14][15]. Poly-ε-caprolactone has been grafted from poly(alkyl methacrylate) or poly(ethylene-co-vinyl alcohol) [10][11][12][13][14]16].…”