Synthesis, characterization and thermal analysis of urea–formaldehyde/nanoSiO2 resins

Fumed silica as a filler for MUPF resin in the process of manufacturing water-resistant plywood

“…The obtained results correspond with those attained by other authors. Introducing small amounts of nano-SiO 2 into the UF resin reduced the formaldehyde release from particleboards, OSB, plywood and medium density fiberboards (MDF) glued with UF resin (Higuchi and Sakata 1981;Lin et al 2006;Roumeli et al 2012;Salari et al 2013). The literature review shows that the reduction of formaldehyde release from boards glued with UF resin modified by a small amount of nano-SiO 2 can be ascribed to absorption properties of the well-developed surface of silica (Leonovich et al 2002;Arafa et al 2004;Gun'ko et al 2005).…”

“…The literature review shows that the reduction of formaldehyde release from boards glued with UF resin modified by a small amount of nano-SiO 2 can be ascribed to absorption properties of the well-developed surface of silica (Leonovich et al 2002;Arafa et al 2004;Gun'ko et al 2005). Researchers also found out that the physical adsorption of formaldehyde is accompanied by the formation of hydrogen bonds between silanol groups on the silica surface and the active groups of the resin and formaldehyde (Roumeli et al 2012;Salari 2013). Obviously, the decrease in formaldehyde emission results from the limited amount of MUPF resin used to produce the investigated plywood.…”

“…It is manifested by the increase in modulus of elasticity, modulus of rupture, internal bond, impact strength as well as thermal and chemical resistance. It is also commonly known that fumed silica enhances thermal, rheological and mechanical properties of various types of adhesives, such as thermoplastic polyurethane (Vega-Baudrit et al 2006), poly(vinyl acetate) (PVAc) (Bonnefond et al 2013), urea-formaldehyde (Leonovich et al 2002;Lin et al 2006;Roumeli et al 2012;Dukarska 2013) and starch-based wood adhesives (Wang et al 2011).…”

“…Researchers investigated mainly the possibility of using fumed silica and colloidal silica as an auxiliary agent in the process of producing particleboards glued with urea-formaldehyde resin. These research works determined the influence of silica on the structure of the cured UF resin and showed that the addition of silica into the resin results in the increase of its viscosity; yet, it does not significantly affect its cross-linking time or thermal stability and the produced boards have better physicomechanical properties (Leonovich et al 2002;Lin et al 2006;Roumeli et al 2012). Owing to the anti-sedimentation properties of nanoSiO 2 , it was possible to produce, by using phenolformaldehyde resin, water-resistant plywood of light-color adhesive bonds (Dukarska and Łęcka 2009).…”

Effects of different nanoclay loadings on the physical and mechanical properties of Melia composita particle board

“…However there is report of compactness of strips having more effect on oriented strand lumber when prepared with different concentration of UF resin along with nano-silane (Taghiyari et al, 2016a). One of the ways to decrease the formaldehyde emission of the UF boned panels is to use nano-fillers such as nanoclay and nano-SiO 2 because these materials have strong absorbability as well as high barrier property (Roumeli et al, 2012). Taghiyari et al (2013a) observed that wollastonite nano-fibers contribute to bond formation between wood chips when applied; consequently they can improve physical and mechanical properties of particle board.…”