Use of Thymus Plants as an Ecological Filler in Urea-Formaldehyde Adhesives Intended for Bonding Plywood

• Published in: Processes Vol. 10; no. 11; p. 2209
• Main Authors: Mohamed Abdoul-Latif, Fatouma, El Montassir, Zineb, Ainane, Ayoub, Gharby, Said, Sakar, El Hassan, Merito, Ali, Mohamed, Jalludin, Ainane, Tarik
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.10.2022
• Subjects: Adhesives; Aldehydes; Ammonium; Ammonium sulfate; Analysis; Aqueous solutions; Bend strength; Bond strength; Chemical properties; Differential thermal analysis; Diffraction; Fillers; Flour; Formaldehyde; Fourier analysis; Fourier transforms; Heat resistance; Herbal medicine; Hot pressing; Infrared analysis; Infrared spectroscopy; Mechanical properties; Medicinal plants; Medicine, Botanic; Medicine, Herbal; Modulus of elasticity; Panels; Physicochemical properties; Plywood; Polyphenols; Radiation; Raw materials; Scanning electron microscopy; Shear strength; Spectrum analysis; Statistical analysis; Urea; Urea formaldehyde resins; Variance analysis; Viscosity; X-ray diffraction; X-rays; Morocco
• ISSN: 2227-9717; 2227-9717
• DOI: 10.3390/pr10112209

Innovative adhesive formulations have been developed in the laboratory based on urea-formaldehyde resin by adding medicinal plants to an industrial adhesive formulation containing raw materials: urea-formaldehyde resin, urea, ammonium sulphate and starch. Specifically, Thymus species (Thymus bleicherianus, Thymus capitates, Thymus satureioides, Thymus vulgaris and Thymus zygis) replaced part of the starch and were considered as the second filler in the formulations. The physico-chemical properties of the resulting adhesive formulations, such as: pH, viscosity, gel time, solids content, density, concentration of free formaldehyde and color were measured, and characterized using Scanning Electron Microscope (SEM), X-ray Diffraction (XRD), Differential Thermal Analysis (DTA), Thermogravimetric Analysis (TGA) and Fourier Transform Infrared spectroscopy (FTIR). In order to evaluate the mechanical performances of adhesive formulations based on plants, plywood panels were produced and their mechanical properties were studied. These mechanical properties included the shear strength, bending strength and the modulus of elasticity. The performance of these panels is comparable to that of plywood panels made using the standard adhesive formulation. From the results obtained, and following the statistical studies, the new adhesive formulations based on plants have the same physico-chemical properties, the same morphologies, and the same mechanical properties. Moreover, the novel adhesives are more viscous, and they have less free formaldehyde content than the commercial formulation.