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. GRAPHICAL ABSTRACT
Chemical modification of kraft lignin from Pinus caribaea (Sénécl.) W.H.G. was performed with cyclic anhydrides (succinic, maleic and glutaric) assisted by microwave radiation. Esterification of the lignin was proven by the mass increase and Fourier Transform Infrared (FTIR) spectroscopy. Aqueous suspensions of bentonite were prepared using unmodified lignin and the corresponding derivatives as dispersants. Suspensions were evaluated in term of stability, viscosity and dispersibility. The esterified derivatives showed better dispersing properties than the neat lignin because the derivatives-based suspensions were less viscous. The dispersing properties of lignin and the esterified derivatives were compared with those of a high-molecular-weight lignin fraction obtained by ultrafiltration. In addition, two commercial lignosulfonate dispersants commonly used for drilling muds were used as references. The high-molecular-weight esterified derivatives proved to be better dispersants than their unfractionated counterparts. In general, the esterified derivatives showed similar properties to those obtained with the commercial dispersants. Modified lignin based on succinic-, maleic- and glutaric-anhydride is expected to play a key role in the design of novel bio-based dispersants for drilling-mud applications.
Chile is among the leading global exporters of pulp and paper, supported by extensive plantations of Pinus radiata and Eucalyptus spp. This review synthesizes recent progress in the valorization of forestry biomass in Chile, including both established practices and emerging bio-based applications. It highlights advances in lignin utilization, nanocellulose production, hemicellulose processing, and tannin extraction, as well as developments in thermochemical conversion technologies, including torrefaction, pyrolysis, and gasification. Special attention is given to non-timber forest products and essential oils due to their potential bioactivity. Sustainability perspectives, including Life Cycle Assessments, national policy instruments such as the Circular Economy Roadmap and Extended Producer Responsibility (REP) Law, are integrated to provide context. Barriers to technology transfer and industrial implementation are also discussed. This work contributes to understanding how forestry biomass can support Chile’s transition toward a circular bioeconomy.