Preformed Amide-containing biopolymer for Improving the Environmental Performance of Synthesized Urea–formaldehyde in Agro-fiber Composites

Abstract

Investigations have continued for production high performance agro-based composites using environmentally acceptable approaches. This study examines the role of adding amide-containing biopolymers during synthesis of urea-formaldehyde (UF) on properties of adhesive produced, especially its adhesion potential. The environmental performance of UF-resin synthesized in the presence of modified amide-containing biopolymer was evaluated by evaluating the free-HCHO of both adhesive (during processing) and of the eventual engineered composite product. Also, the benefits of this synthesis-modified adhesive in enhancing the bondability of sugar-cane fibers used in engineered composite panels was evaluated and compared to using UF-resin. The results obtained show that, static bending of the produced composites varied from 27.7 to 33.13 N/mm 2 of modulus of rupture (MOR) and from 2860 to 3374 N/mm 2 of Modulus of Elasticity (MOE); while for internal bond (IB) it's varied from 0.64 to 0.866 N/mm 2 . Based on the ANSI and EN Standards modified UF-based agro composites produced meet the performance requirements for high grade particleboards with respect to static bending strength. These agro-based composite also tested out as having free-HCHO values of *13 mg/100 g board.

Synthesis, structure, and characterization of glyoxal‐urea‐formaldehyde cocondensed resins

“…Urea-formaldehyde (UF) resins are currently the major wood adhesive for the manufacture of interior-use wood composite boards such as particleboards, medium-density fibreboards and plywood owing to their low cost, fast curing, and good performance. [1][2][3] However, they present the major disadvantage of toxic formaldehyde emission from UF-bonded products. Formaldehyde (LD50 rat 100 mg/kg; LD50 mouse 42 mg/kg) 4 is found to cause cancer and to cause irreversible health effect.…”

“…Thus, to decrease F emission, many approaches have been tried during the last decades and much progress has been achieved. [5][6][7][8] The main drawback of UF resin is on one hand, the unreacted F which remains in the final resin. On the other hand, F is emitted because both methylolation and condensation reactions in UF resins are reversible.…”

Thermal degradation of urea‐formaldehyde cellulose composites filled with aluminum particles: Kinetic approach to mechanisms

“…The obtained syrupy solution is mixed with cellulose to form powder for subsequently molding into solid, known as urea‐formaldehyde cellulose or concisely UFC . UFC thus formed finds industrial applications in textiles, paper, foundry and molds, wood gluing and electrical appliances casings . A fascinating class of materials is developed by loading UFC with metal particles, which is economical, environmentally friendly and multipurpose .…”

Hydroxymethyl furfural-modified urea–formaldehyde resin: synthesis and properties

“…Other adhesives such as phenol-formaldehyde resins (Fink 2005) have also been used in wood industry. However, because of their very low costs, non-flammability, high curing rate, and the light color, UF resins are still used in vast amounts and as the most important adhesive by far in the production of wood based panels (Zorba et al 2008;Abdullah and Park 2010;Basta et al 2011;Patel et al 2013). UF resins show some disadvantages, for example, low water-susceptibility (Christjanson et al 2002(Christjanson et al , 2006, low heat-stability (Dim 2011), non-uniform film formation (Singh et al 2013) and, most importantly, emission of carcinogenic free formaldehyde (Birkeland et al 2010).…”