Enhancing environmental performance of formaldehydebased adhesive in lignocellulosic composites Part II

Purpose To investigate a new approach for the prevention of lignocellulosic composites based on agrofibres e.g. sugarcane bagasse from the emission of toxic formaldehyde. Designmethodologyapproach Five organic polymer containing nitrogenurea formaldehyde UF adhesive systems were used as bonding agents for bagasse fibres. The environmental performance of the lignocellulosic composites prepared were evaluated in terms of the effect of the organic polymers on the percentage of free formaldehyde in the adhesive system and the adhesion properties static bending and water resistance properties of the composite produced, in comparison with that prepared from unmodified UF. The nitrogen content of the polymer and the amount of organic polymers incorporated in the adhesive system were optimised using the 3D response surface methodology and the multilinear regression technique. Findings All investigated organic polymers crude PAMgstarch, PAMgstarch, PAM, CEstarch and Cmstarch were found to enhance the performance of the UFadhesive for producing environmentally friendly bagassecomposite, whereas the reduction of freeHCHO in UFadhesive systems ranges from 26 to 100 percent. The performance of the composite produced exceeded the ANSI requirements for Grade H3 particleboard. Research limitationsimplications Despite the success in improving the performance mechanical properties and reduction of freeformaldehyde of the UFadhesive and agrocomposites, the polymers needed to be incorporated at a high percentage 1220 percent resulting in reduced water resistance of the product. Further investigation is needed to resolve this problem. Practical implications The approach developed provided a simple and practical solution to enhancing the performance of waste agrofibres and commercial amino adhesive in the production of high performance lignocellulosic composite. Originalityvalue The organic polymers UF adhesive systems are novel bonding agents for agrofibres and could be used in timber mills for production of particleboard and medium density fibreboard.