Functionalization of softwood residue generated in logging and forestry for fabrication of environmentally friendly composite materials based on recycled polymer for building interior completion

This work aimed to study the effect of the chemical composition and thermal characteristics of three suberinic acids extracted under different conditions (SAs pH 2, SAs pH 5, SAs Et-OH) on the processing and properties of a recycled polypropylene-based composite reinforced with pine waste alkaline-treated (2% NaOH, 90 ˚С and 1.5 h) microfibers. The composites filled with the alkaline-treated pine microfibers and incorporated with the suberinic acids were evaluated in terms of processing, mechanical properties and water uptake. The results indicate that the studied suberinic acids, present at a concentration of 4.0%, were effective as internal lubricants for the composite incorporating both recycled polypropylene and alkaline-treated pine sawdust. Due to their unique chemical composition and molecular mass distribution, the suberinic acids extracted from an ethanol medium were found to be the most effective.