The influence of silane coupling agent and poplar particles on the wettability, surface roughness, and hardness of UF-bonded wheat straw (Triticum aestivum L.)/poplar wood particleboard

We used silane coupling agents to improve the bonding ability between wheat straw particles and UF resin, and investigated surface properties (wettability and surface roughness) and hardness of particleboard made from UF-bonded wheat straw (Triticum aestivum L.) combined with poplar wood as affected by silane coupling agent content and straw/poplar wood particle ratios. We manufactured one-layered particleboard panels at four different ratios of straw to poplar wood particles (0%, 15%, 30% and 45% wheat straw) and silane coupling agent content at three levels of 0, 5% and 10%. Roughness measurements, average roughness (Ra), mean peak-to-valley height (Rz), and root mean square roughness (Rq) were measured on unsanded samples by using a fine stylus tracing technique. We obtained contact angle measurements by using a goniometer connected to a digital camera and computer system. Boards containing greater amounts of poplar particles had superior hardness compared to control samples and had lower wettability. Panels made with higher amounts of silane had lower Rq values.