Preparation Optimization by Response Surface and Performance Characterization of a New Starch-Based Adhesive

In this study, a new kind of green, pollution-free, and renewable starch-based adhesive (CP-dialdehyde starch [DSt]) was prepared by using corn starch as raw material, which was oxidized into DSt by sodium periodate, grafted with chitosan, and cross-linked with polyethylene glycol 200 (PEG-200). The preparation parameters of CP-DSt adhesive were optimized by response surface methodology, and it was characterized by Fourier transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), scanning electron microscope (SEM), and x-ray spectroscopy (EDAX). The results showed that when the PEG-200 dosage was 53% (w/w, dry starch basis), the dosage of chitosan was 15.2% (w/w, dry starch basis), the reaction time was 2.4 h, and the reaction temperature was 41°C, the comprehensive properties of the adhesive were better. The dry shear strength of the CP-DSt adhesive can reach 3.04 MPa. When the adhesive was used to bond paper-based materials, the tensile index increased from 21.21 to 24.65 N m/g, an increase of 16.22%; the tear resistance index increased from 1.75 to 2.03 kPa m2/g, an increase of 16.0%; the ring pressure index increased most significantly, increasing by 30.28%. The SEM analysis showed that the bonding strength of CP-DSt adhesive was greater than the internal bonding strength of the boxboard, and the water contact angle was 45.9°, indicating that CP-DSt adhesive also had a certain hydrophobicity. This paper provided a new idea for the preparation of the high-quality starch-based adhesive, which had a wide application prospect in paper adhesive. © 2024 Wiley-VCH GmbH.