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

ABSTRACT 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 m 2 /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.