(Characterization of Pine (Pinus merkusii Jungh et de Vriese) Tannin Bark)

Abstract

Adhesive is the one of main components required in the composite wood processing industry. Synthetic adhesives, that are commonly used in the processing of wood composites, contain formaldehyde emissions which are harmful for both the environment and human health, so alternatives are needed to reduce their use. Tannin is a polyphenol compound derived from plants which has the potential to be used as a bioadhesive. Large quantities of tannins can be found in bark, especially in Pinus merkusii bark wood. This study aims to determine the physical and chemical characteristics of Pinus merkusii bark tannin extracts. Tannin was obtained by extraction method with hot water solvents. The physical properties observed were color, solid content, and viscosity. The chemical properties observed were pH, FTIR analysis, and GCMS analysis. The liquid tannin extract obtained was light brown, had solid content of 0.30% and viscosity of 2.65 centipoises. Pine tannin extract has an acidic pH of 4.23. After analyzing the functional groups by using FTIR test, the functional groups contained in Pinus merkusii bark extracts were hydroxyl groups, carbonyl groups, CH alkane groups, aromatic rings, aldehydes, and ether groups. GCMS analysis result showed that pine bark extract contained some of phenolic compound with 7,75 % of concentration. Due to the presence of this phenolic group, tannins can react to formaldehyde and undergo polymerize condensation to become wood adhesive.