Properties of peanut meal-based wood adhesives enhanced by urea and epichlorohydrin

In this study, urea (U) and epichlorohydrin (ECH) were used to enhanced the properties of peanut meal (PM)-based wood adhesives and the modification mechanism were investigated. We determined the dry and wet shear strength, apparent viscosity, and solid content of a PM-based adhesive (adhesive A) and of its derivatives modified with U, U/ECH, and ECH (adhesives B, C, and D), respectively. Adhesive C showed dry shear strength of 1.79 MPa (compared with 0.53 MPa for adhesive A), its water resistance was significantly enhanced, and its wet shear strength was 0.92 MPa (compared with 0 MPa for adhesive A). Moreover, compared with adhesive A, the apparent viscosity increased from 819 to 24968 mPa·s, and the solid content of adhesive C increased from 21.60% to 25.14%. The infrared spectra results suggested that ECH reacted with U-treated PM, forming a dense, cross-linked network. Crystallinity of adhesive C reached 11.0% compared with 2.7% for adhesive A, indicating that the molecular structur...

本研究以尿素（Urea, U）与环氧氯丙烷（Epichlorohydrin, ECH）为改性剂，优化花生粕（Peanut Meal, PM）基木材胶粘剂的性能，并对其改性机理进行了探究。本研究分别测定了纯PM基胶粘剂（胶粘剂A），以及经U、U/ECH、ECH改性得到的其衍生物（分别对应胶粘剂B、C、D）的干剪切强度、湿剪切强度、表观黏度与固含量。结果显示，胶粘剂C的干剪切强度达1.79 MPa（胶粘剂A仅为0.53 MPa），其耐水性能得到显著提升，湿剪切强度为0.92 MPa（胶粘剂A的湿剪切强度为0 MPa）。此外，与胶粘剂A相比，胶粘剂C的表观黏度从819 mPa·s提升至24968 mPa·s，固含量从21.60%增至25.14%。红外光谱分析结果表明，环氧氯丙烷与经尿素改性的花生粕发生反应，形成了致密的交联网络结构。胶粘剂C的结晶度达11.0%，而胶粘剂A仅为2.7%，这表明其分子结构……