Urea-formaldehyde resins: production, application, and testing

Innovation in Polymer Science and Technology 2016

材料科学;化学

Nuryawan, A.^1 ; Risnasari, I.^1 ; Sucipto, T.^1 ; Heri Iswanto, A.^1 ; Rosmala Dewi, R.^2,3

Department of Forest Products Technology, Faculty of Forestry, University of Sumatera Utara, Medan, Indonesia^1

Veterinarian, Faculty of Agriculture, University of Sumatera Utara, Medan, Indonesia^2

Veterinarian, Faculty of Agriculture, University of Tjut Nyak Dhien, Medan, Indonesia^3

关键词: Composite products;    Condensation product;    Formaldehyde emission;    Indoor environment;    Japanese industrial standards;    Living environment;    Two-step reactions;    Wood-based composites;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/223/1/012053/pdf
DOI  :  10.1088/1757-899X/223/1/012053

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Urea-formaldehyde (UF) resin, one of the most important formaldehyde resin adhesives, is a polymeric condensation product of formaldehyde with urea, and being widely used for the manufacture of wood-based composite panels, such as plywood, particleboard, and fiberboard. In spite of its benefits such as fast curing, good performance in the panels (colorless), and lower cost; formaldehyde emission (FE) originated from either UF resin itself or composite products bonded by UF resins is considered a critical drawback as it affects human health particularly in indoor environment. In order to reduce the FE, lowering formaldehyde/urea (F/U) mole ratio in the synthesis of the UF resin was done. In this study, synthesis of UF resins was carried out following the conventional alkaline-acid two-step reaction with a second addition of urea, resulting in F/U mole ratio around 1.0, namely 0.95; 1.05, and 1.15. The UF resins produced were used as binder for particleboard making. The board was manufactured in the laboratory using shaving type particle of Gmelina wood, 8% UF resin based on oven dry particle, and 1% NH4Cl (20%wt) as hardener for the resin. The target of the thickness was 10 mm and the dimension was 25 cm x 25 cm. The resulted particleboard then was evaluated the physical and the mechanical properties by Japanese Industrial Standard (JIS) A 5908 (2003). Further, the resulted particleboard also was used for the mice cage's wall in order to mimic the real living environment. After four weeks exposure in the cages, the mice then were evaluated their mucous organs as well as their blood. The experiment results were as follows: 1) It was possible to synthesis UF resins with low F/U mole ratio; 2) However, the particleboard bonded UF resins with low F/U mole ratio showed poor properties, particularly on the thickness swelling and modulus of elasticity; 3) There was no significant differences among the mucous organs of the mice after a month exposure FE originated from cages wall using histopathology assessment.