Análise do uso de diferentes teores de resina fenólica natural a base de tanino para impregnação de madeira de pinus

Abstract

This study aimed to analyze the use of different levels of natural tannin-based phenolic resin for the impregnation of pinus wood in the production of LVL (Laminated Veneer Lumber) plywood panels. The research responds to growing environmental and public health concerns regarding the use of synthetic formaldehyde-based resins, known for their volatile organic compound (VOC) emissions and classified as carcinogenic. Several formulations were developed, varying the percentages of natural tannin, modified tannin (15%, 25%, 35%, and 50%) as well as synthetic phenolic resin (15%, 25%, 35%, and 50%), with the goal of evaluating the impact of this substitution on the physical and mechanical properties of the panels. The samples underwent tests for apparent density, water absorption, thickness swelling, and static bending resistance (Modulus of Rupture - MOR and Modulus of Elasticity - MOE). Additionally, morphological analysis by Scanning Electron Microscopy (SEM) and tests for quantifying formaldehyde and phenol emissions were performed. The results showed that formulations containing up to 25% tannin, both natural and modified, achieved satisfactory physical and mechanical performance, comparable or even superior to the standard panel made with 50% synthetic phenolic resin. Panels with 50% tannin showed structural fragility and high water absorption, making them unsuitable for moisture-resistant applications. The study concludes that the partial replacement of phenolic resin with tannins is technically feasible, helping reduce formaldehyde emissions and contributing to the sustainability of the wood panel industry without compromising final product quality. The research highlights the potential of natural adhesives, such as tannins, as an eco-friendlier alternative in wood composite production. [resumo fornecido pelo autor]