Nucleation, Crystallization, and Thermal Fractionation of Poly (ε‐Caprolactone)‐Grafted‐Lignin: Effects of Grafted Chains Length and Lignin Content

• Published in: Journal of polymer science. Part B, Polymer physics Vol. 53; no. 24; pp. 1736 - 1750
• Main Authors: Pérez–Camargo, Ricardo A, Saenz, Guery, Laurichesse, Stéphanie, Casas, María Teresa, Puiggalí, Jordi, Avérous, Luc, Müller, Alejandro J
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley 15-12-2015; Wiley Subscription Services, Inc
• Subjects: Annealing; antinucleation; Chains (polymeric); composite polymers; crystal structure; Crystallinity; Crystallization; crystallization kinetics; Fractionation; graft copolymers; Hydrogen bonding; hydrogen bonding formation; lignin; Melting; melting point; Nucleation; poly(ε–caprolactone); temperature; thermal properties
• ISSN: 0887-6266; 1099-0488
• DOI: 10.1002/polb.23897

Poly(ε‐caprolactone)‐grafted‐lignin (PCL‐g‐lignin) copolymers with 2 to 37 wt % lignin are employed to study the effect of lignin on the morphology, nucleation, and crystallization kinetics of PCL. Lignin displays a nucleating action on PCL chains originating an intersecting lamellar morphology. Lignin is an excellent nucleating agent for PCL at low contents (2–5 wt %) with nucleation efficiency values that are close to or >100%. This nucleating effect increases the crystallization and melting temperature of PCL under nonisothermal conditions and accelerates the overall isothermal crystallization rate of PCL. At lignin contents >18 wt %, antinucleation effects appear, that decrease crystallization and melting temperatures, reduce crystallinity degree, hinder annealing during thermal fractionation and significantly retard isothermal crystallization kinetics. The results can be explained by a competition between nucleating effects and intermolecular interactions caused by hydrogen bonding between PCL and lignin building blocks. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015, 53, 1736–1750