نوع مقاله : مقاله کامل علمی پژوهشی
نویسندگان
1 دانشجوی دکتری مهندسی صنایع چوب و فراوردههای سلولزی، دانشکده منابع طبیعی، دانشگاه زابل، زابل، ایران
2 دانشیار، گروه علوم و صنایع چوب و کاغذ، دانشکده منابع طبیعی، دانشگاه زابل، زابل، ایران.
3 دانشیار ، گروه علوم و صنایع چوب و کاغذ، دانشکده منابع طبیعی، دانشگاه زابل، زابل، ایران.
4 دانشیار، گروه شیمی، دانشکده علوم، دانشگاه زابل، زابل، ایران.
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and Objective: The particleboard industry is important due to its wide application in construction and decoration, where urea-formaldehyde adhesives are commonly used due to their cost-effectiveness; however, the emission of urea-formaldehyde gas from these boards is a serious environmental and health challenge that can lead to health hazards and even cancer; therefore, current research has focused on the use of additives such as carbazide and aminopropyltriethoxysilane to reduce this formaldehyde emission from the final products. The aim is to investigate the effect of carbazide, aminopropyltriethoxysilane (APTES) on the formaldehyde emission rate and physical-mechanical properties of particleboard made with urea-formaldehyde (UF) resin produced by Shiraz and Samed Adhesives Companies.
Materials and Methods: This study investigates the manufacture of particleboard using coarse and fine wood chips, Samed Mashhad, Shiraz urea formaldehyde adhesive, hardener, and various amounts of the toxic substance carbazide (1, 1/5 grams) and aminopropyltriethoxide (2, 4, 6 percent); dried wood chips were mixed with these materials and the chip cake (with a ratio of 60 to 40 coarse to fine wood chips) was pressed at 190 degrees Celsius and a certain pressure to produce boards with a density of 0/7 grams per cubic centimeter and a thickness of 16 millimeters; finally, the manufactured boards were stored for two weeks under standard conditions and were subjected to quality evaluation, strength and flexural modulus, internal adhesion, formaldehyde diffusion, water absorption, thickness swelling, and microscopic examinations.
Results: The results showed that the Shiraz control adhesive had better mechanical performance, including its higher flexural strength, internal adhesion, and flexural modulus. Semicarbazide in Shiraz adhesive with 1 g showed the highest flexural strength and with 1/5 g the highest internal adhesion and flexural modulus, and aminopropyltriethoxysilane in Shiraz adhesive with 2% showed the highest flexural strength, internal adhesion, and flexural modulus. The lowest water absorption and thickness swelling (2 and 24 hours) were observed in Shiraz adhesive. Regarding water absorption after 2 hours, Samed Mashhad adhesive with 6% aminopropyltriethoxysilane had the lowest water absorption, but after 24 hours, Shiraz adhesive with the same concentration of 6% showed the lowest water absorption. Formaldehyde emission in Shiraz adhesive was generally lower, and a significant reduction was observed in Shiraz adhesive with the addition of 1/5 g semicarbazide and 2% triethoxide. SEM and FTIR analyses confirmed these results and showed that strong chemical bonds (including C=O, N-H, C-H, and Si-O-Si groups) between the components led to increased adhesion, integrity, and compatibility between the adhesive polymer and wood chips.
Conclusion: The best mechanical properties (highest flexural strength and internal adhesion) were obtained using Shiraz adhesive with 2% aminopropyltriethoxysilane, while the highest flexural modulus of elasticity was obtained with the Shiraz control adhesive; in terms of water absorption, the lowest value in 2 hours was for Samed Mashhad adhesive with 6% additive and in 24 hours for Shiraz adhesive with 6% additive, and the lowest thickness swelling was observed in Shiraz adhesive with 2% triethoxide; in terms of safety, the lowest formaldehyde gas emission was for Samed Mashhad adhesive with 6% triethoxide; In addition, microscopic (SEM) studies showed that the addition of silane improved adhesion and structural uniformity, and FTIR analysis also confirmed the establishment of effective chemical interactions between the adhesive components and wood chips.
کلیدواژهها [English]