Preparation of a strong, high prepressing intensity, and multifunction soybean protein adhesive by using hyperbranched functional polymer. (February 2023)

• Record Type: Journal Article
• Authors: Liu, Zheng; Liu, Tao; Zhang, Jieyu; Li, Yue; Luo, Jing; Li, Jianzhang; Shi, Sheldon Q.; Gao, Qiang; Mao, An
• Is Part Of: Polymer testing. Volume 119(2023)
• Publication Date: 2023-02
• Subjects: Soybean protein adhesive -- Hyperbranched functional polymer -- Multifunctionality; Polymers -- Testing -- Periodicals; Polymères -- Tests -- Périodiques; 620.1920287
• DOI: 10.1016/j.polymertesting.2023.107931
• Languages: English
• ISSNs: 0142-9418

Abstract

Abstract: The preparation of a soybean protein adhesive with good prepressing intensity, mildew proof, flame retardant, and high bond strength are conducive to the wide application of a soybean protein adhesive, which is important but challenging for the wood-based panel industry. In this study, two hyperbranched functional polymers were designed. Hyperbranched polyamide (HP) was grafted by 3-hydroxyphenylphosphinyl-propanoic acid (PPA) to obtain PPA@HP and then combined with self-synthesized epoxidized tannin (ETA) to modify the soybean protein adhesive. The hyperbranched functional polymer PPA@HP and ETA reacted with soybean protein to form a hyperbranched cross-linking structure and a hydrogen bond network, which noticeably improved the toughness and bond strength of the adhesive. The wet shear strength of the resultant plywood was improved by 110.9% to 1.35 MPa. The formed hyperbranched hydrogen bond network also significantly improved the prepressing intensity (by 129.0% to 0.71 MPa). In addition, the anti-mildew time increased from 24 h to 120 h. The time to block combustibles increased from 5 s to 80 s, and the limiting oxygen index improved from 23.5% to 38.5%. The use of hyperbranched functional polymers created covalent and non-covalent hybrid networks provides an effective and convenient strategy for developing high-strength and multifunctional composites, such as bio-adhesives, hydrogels, and films. Highlights: Two hyperbranched functional polymer PPA@HP and ETA was designed and tested. PPA@HP and ETA were combined with SPI to obtain protein-based adhesive. The adhesive has high bond strength (1.35 MPa) and prepressing intensity (0.71 MPa). The anti-mildew time and the limiting oxygen index were reached 120 h and 38.5%. A new facile and universality strategy for fabricating multifunction biocomposites.