Polyurethane elastic cross-linking agent, high-strength and high-toughness vegetable protein adhesive and application

Abstract

The invention relates to a polyurethane elastic cross-linking agent, a high-strength and high-toughness vegetable protein adhesive and application. The polyurethane elastic cross-linking agent is prepared from the following raw materials: isocyanate, polyol, a catalyst, 2,2-dimethylolpropionic acid, a small molecular diol chain extender, plant polyphenol, a neutralizer and bisulfite. The polyurethane elastic cross-linking agent provided by the embodiment of the invention has excellent compatibility. The vegetable protein adhesive prepared from the polyurethane elastic cross-linking agent is synchronously enhanced in the bonding strength and toughness. According to the invention, the polyurethane elastomer is used as an energy dissipation element, and a physical-covalent double cross-linkednetwork is constructed in a protein matrix through main chain design, so that the design of the high-strength high-toughness vegetable protein adhesive is realized.

Description

Technical field [0001] The invention relates to an adhesive, in particular to a polyurethane elastic crosslinking agent and a high-strength vegetable protein adhesive and applications. Background technique [0002] At present, the adhesives used in the preparation of wood-based panels are still mainly formaldehyde-based (urea-formaldehyde resins, phenolic resins and melamine resins) synthetic resins, and the issue of formaldehyde release during the manufacturing, storage and use processes is critical to the safety of human settlements and the industry. Development causes major harm. [0003] It is of great significance to convert renewable resources such as bulk agricultural and forestry products into high value-added environmentally friendly bio-based composite materials. At present, high-yield, easily available, and renewable materials such as plant protein, starch and lignin have been developed by researchers for bio-based adhesives to replace formaldehyde-based synthetic resin...

AI Technical Summary

Problems solved by technology

Although the cross-linking density of protein adhesives is improved, water resistance and mechanical rigidity are significantly improved, but these treatments significantly aggravate the brittleness of the wood-based panel adhesive layer, resulting in a lack of energy dissipation to maintain the impact resistance of the adhesive layer

This phenomenon leads to the splitting of the adhesive layer caused by twisting during the handling of wood-based panels, especially in the process of wood-based panel processing. The stress of mechanical processing causes problems such as chipping of wood-based panels, which significantly increases the processing of the board. Adhesives with high residual rate have greatly hindered the further development and promotion of vegetable protein-based adhesives

[0004] In order to solve the bottleneck problem of current vegetable protein adhesives, elastic bases (such as rubber, vegetable oil, etc.) are used as cross-linking components to improve the bonding performance, in order to achieve strength and toughness with the help of its own toughness and the constructed cross-linked network. Although this technical solution has a reference for the strengthening and toughening adhesive, it is not conducive to the improvement of the performance of the adhesive due to the problem of poor compatibility.

The design based on high-performance natural protein-based materials (such as spider silk, silk, etc.) provides new theoretical guidance for the strengthening and toughening of plant protein adhesives. However, this technology requires the use of nano-fillers or polymer fragments to design their molecules. The construction of a highly ordered microphase separation structure can fully reflect the excellent performance, and the cumbersome preparation process is not conducive to the industrial production of wood-based panels

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