Condensed tannin-based polyurethane as functional modifier of PLA-composites

GARCÍA, D.; SALAZAR, J.P.; RIQUELME, S.; DELGADO, N.; PACZKOWSKI, S.:
Polymer-Plastics Technology and Engineering, Volume 57(8), January 2018, Pages 709-726

DOI:10.1080/03602559.2017.1344855

Abstract

Novel polylactic acid-based composites were prepared for the first time by melt-blending urethanization using bark polyflavonoids, and polymeric methyl diisocyanate. Rheological, morphological, structural, thermal, and mechanical properties were studied. Polymerization between polyflavonoids and isocyanate during the melt-blending was demonstrated by spectroscopy, confocal microscopy, and thermal analysis. Polyflavonoids improved the blend processability and affected the polylactic acid-crystallization, blend-urethanization, and flexural features. Polyphenols act as nucleating agent, and the effect was highly influenced by the polymeric methyl diisocyanate-charge, and the polyflavonoids-content. Low polymeric methyl diisocyanate-loading (10 wt%) degrades the elasticity modulus (E), while the highest polymeric (20 wt%) improved the miscibility between the polylactic acid polymer-matrix and the polyflavonoids.

SEE MORE