Fast atmospheric plasma treatment of LLDPE film for preparing formaldehyde emission-free plywood

Abstract

Atmospheric plasma was utilized to modify linear low-density polyethylene (LLDPE) film. On that basis, formaldehyde emission (FE)-free plywood was prepared using plasma-treated LLDPE film as the adhesive. Obtained results suggested that atmospheric plasma treatment leads to grafting of multiple oxygen-containing groups, thus evidently elevating the surficial polarity of LLDPE. Enhanced interaction between polar groups contributed to improve interfacial compatibility and interfacial adhesion between LLDPE and poplar veneer. Prepared by plasma treatment on both LLDPE and veneer, LLDPE/poplar plywood exhibited fine shear strength (around 0.87 MPa) and dynamic mechanical properties. Furthermore, the mechanical properties of plasma-treated LLDPE/poplar plywood were similar to those prepared by coupling agent treatment. It is believed that plasma treatment is a promising way to overcome the inherent hydrophobic surface of LLDPE and therefore improve the interfacial adhesion between LLDPE and wood. LLDPE/poplar plywood can be effectively manufactured using plasma treatment with reduced chemical consumption and total cost. The FE of prepared LLDPE/poplar plywood was remarkably low, indicating its suitability for indoor applications.