Utilization of Suberinic Acids Containing Residue as an Adhesive for Particle Boards

Abstract

The birch (Betula spp.) outer bark is a valuable product rich in betulin. After removal of betulin extractives, suberin containing tissues are left. Suberin is a biopolyester built from α,ω-bifunctional fatty acids (suberinic acids), which after depolymerization together with lignocarbohydrate complex is a potential adhesive as a side-stream product (residue) from obtaining suberinic acids for polyol synthesis. In this work, we studied the utilization possibilities in particleboards of the said residue obtained by depolymerization in four different solvents (methanol, ethanol, isopropanol and 1-butanol). The adhesives were characterised by chemical (acid number, solubility in tetrahydrofuran, epoxy and ash content) and instrumental analytical methods (SEC-RID, DSC, TGA and FTIR). Based on the results of mechanical characteristics, ethanol was chosen as the most suitable depolymerization medium. The optimal hot-pressing parameters for particleboards were determined using the design of experiments approach: adhesive content 20 wt%; hot-pressing temperature 248 °C, and hot-pressing time 6.55 min.

Rigid Polyurethane Foams as Thermal Insulation Material from Novel Suberinic Acid-Based Polyols

“…In this range, the strongest bonds in the PUR backbone degrade [ 34 ]. Decomposition of suberin-like structures has been reported around the temperature of 200 °C, ~400 °C, and 450 °C [ 41 ], which coincides with the first and third degradation stages for rigid PUR foams.…”

Processing and Properties of Wood-Plastic Composite Containing Alkali-Treated Birch Wood Shavings and Bioadditive Obtained by Biorefinery of Birch Bark

“…Depolymerization of suberin is the most widely exploited mode for obtaining suberinic acids (SAs) [30,31], which represent a complex of fatty acids (long-chain aliphatic saturated, unsaturated, and dicarboxylic acids) covalently bonded with aromatic structures (Figure 1). Due to the peculiarities of the chemical composition, SAs can be used as a formaldehyde-free adhesive for plywood [33][34][35], particle boards [36][37][38], and as a raw material for obtaining polyols for polyurethanes [32]. As mentioned, fatty acids and their esters are the most commonly used lubricants for optimizing the processing of WPCs in extrusion.…”

“…The main objective of the study was to examine if suberinic acids, being the wood biorefinery product, could be used to replace a synthetic lubricant in the rPP/PLA-birch wood composite by determining the effect of the biorefinery product on the processing of the fabricated composite and its properties. Due to the peculiarities of the chemical composition, SAs can be used as a formaldehydefree adhesive for plywood [33][34][35], particle boards [36][37][38], and as a raw material for obtaining polyols for polyurethanes [32]. As mentioned, fatty acids and their esters are the most commonly used lubricants for optimizing the processing of WPCs in extrusion.…”

Qualitative Differences and Emission Persistence of Volatile Organic Compounds from Bio-Based Particleboards

“…As a reaction to the industry’s challenge related to formaldehyde emission, bio-based adhesives are on the research top, generally comprising lignin, tannins, protein, and starch [ 12 ]. A very new and promising bio-based adhesive has been revealed in the form of suberinic acids containing binder from birch wood outer bark [ 13 ] investigated for application in particleboard [ 14 ] and plywood [ 15 ]. However, very few studies have investigated the VOC profiles of binder-less and bio-adhesive-bonded particleboards.…”