Data from: 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 structure
of the PM protein in adhesive C became more regular and compact, as
confirmed by X-ray diffraction measurements. Thermogravimetry tests showed
that adhesive C had higher thermal stability than adhesives A, B, and D.
Scanning electron microscopy images revealed that adhesive C also
exhibited the smoothest fracture surface.