Luisa Hora de Carvalho, PhD in Chem. Eng., is Professor of Wood Science and Engineering at Polytechnic Institute of Viseu, Portugal and researcher at LEPABE-University of Porto. She is a member of ARCP-Association Competence Network in Polymers and has been engaged in several projects with industry in the area of synthetic and natural adhesives for wood and cork based composites, lightweight panels, formaldehyde emissions, high-pressure laminates and wood machining/finishing.

Luisa Hora de Carvalho is graduated in Chemical Engineering. She obtained a MSc in Wood Science from the Université Henri Poincaré Nancy I (currently Université de Lorraine) and a PhD in Chemical Engineering from FEUP. She is currently coordinator professor at ESTGV(IPV-Polytechnic Institute of Viseu) where she teaches in the course of Licenciatura in Furniture Technology and Design and is the President of the Wood Engineering Deparment Council. She is also invited Professor at ESTGF(IPP-Polytechninc Institute of Porto in the course of “Licenciatura” in Wood Technology. She is staff member of LEPABE (Laboratory for Process Engineering, Environment, Biotechnology and Energy) and Vice President of the Geral Assembly of ARCP (Association Competence Network in Polymers) and former member of its board of directors (2013-2019). She is also President of SC2-wood-based panels from the national standardisation committee CT14-wood and Technical Expert of IPAC(Portuguese Institute for the Accreditation). She is Vice-President of the General Assembly of APAA (Portuguese Society of Adhesion and Adhesives), which belongs to the European Group of Adhesion Societies (EURADH) and is member of the Editorial Advisory Board of International Journal of Adhesion and Adhesives. Her research interests include wood adhesives (development of new eco-friendly binding systems), wood-based panels (process modeling, formaldehyde and VOCs emissions), high-pressure laminates with innovative functionalities, wood machining/finishing (monitoring and control of processes, evaluation of finished surfaces).

Abstract – Impact of Urea-formaldehyde Synthesis Parameters on Resin and Particleboard Properties

This paper presents a study of two crucial synthesis parameters in the alkaline-acid process of UF resin synthesis: condensation formaldehyde/urea (F/U) molar ratio and U feed rate. The differences in the polymeric structures and the performance of new resins on the particleboards (PBs) properties were analyzed and compared with a standard resin. The molecular weight distribution of the resins was monitored by Gel Permeation Chromatography/Size Exclusion Chromatography (GPC/SEC) and the unreacted oligomers by High-Performance Liquid Chromatography (HPLC). The PBs produced were analyzed following  European standards for physico-mechanical tests and formaldehyde emission. The data obtained were also submitted to a statistical analysis. According to the results, the resin used as standard yielded the best results when the final F/U molar ratio was 1.10 and the resulting PBs presented values of internal bond (IB) of 0.51 and formaldehyde content (F) of 5.1 mg/100 g o.d.b., complying with the market requirements. Additionally, the effect of resin ageing was also studied and the PBs prepared using the best resin upon fifteen days of its production presented similar IB values and even lower F content in relation to those obtained using fresh resin.