Abstract
Response surface methodology was used to optimize the preparation conditions of soy‐based adhesives (SBAs) in this work. The parameters such as the effects and interactions of waterborne polyurethane (WPU) addition level (X1), temperature (X2), and time (X3) on wet shear strength (Y) were investigated. The regression model for SBA preparation was significant (p = 0.0034 < 0.05). The coefficient of determination (R2) of this model was to be 0.9256. According to the results, WPU addition level (X1) had a significant influence on the wet shear strength, whereas reaction temperature (X2) and reaction time (X3) were not significant. The optimal preparation conditions of SBA were 12 wt.% WPU addition level for 101 min at 76°C. Under the optimal conditions, the wet shear strength was 1.07 ± 0.08 MPa, which was in good agreement with the model predicted value. An analysis of FTIR spectra of WPU, soy flour, and soy‐based adhesive further confirmed the validity of the model.
Highlights
Formaldehyde-based adhesives such as urea-formaldehyde (UF), phenol-formaldehyde (PF), and melamine-formaldehyde (MF) are widely applied in wood industry due to their excellent adhesion performance and low cost [1]
Soy flour is one of the research focuses because it has high content of soy protein, and it is abundant, affordable, and readily available [2, 3]. ough soy flour is an attractive raw material for wood adhesives, the application of soy-based adhesives as an alternative of traditional formaldehyde-based adhesives is severely restricted by poor water resistance. en, it is necessary to improve water resistance in order to broaden the application of soy-based adhesives [1, 4]
Wet shear strength was performed by applying waterborne polyurethane (WPU) addition level ranging from 2 wt.% to 14 wt.% with the other reaction conditions as follows: the reaction temperature was 80°C and the time was 120 min
Summary
Formaldehyde-based adhesives such as urea-formaldehyde (UF), phenol-formaldehyde (PF), and melamine-formaldehyde (MF) are widely applied in wood industry due to their excellent adhesion performance and low cost [1]. Formaldehyde-based adhesives derive from fossil resources, which are limited and nonrenewable. Formaldehyde emission caused by massive production and application of formaldehyde-based adhesives is harmful and toxic. Formaldehyde has already been classified as possibly carcinogenic to human health by the World Health Organization (WHO), and the use of formaldehyde-based adhesives may contaminate environment and damage health of workers and consumers, especially infants. Great efforts have been made to develop formaldehyde-free adhesives from natural biomaterials, especially soy flour. Ough soy flour is an attractive raw material for wood adhesives, the application of soy-based adhesives as an alternative of traditional formaldehyde-based adhesives is severely restricted by poor water resistance. En, it is necessary to improve water resistance in order to broaden the application of soy-based adhesives [1, 4]. Soy protein mainly consisted of 20 different kinds of amino acids with various functional groups bonded in the side chains of polypeptide, including hydroxyl (−OH), carboxyl (−COOH), thiol (−SH), and amino (−NH2) [5, 6]. rough reacting with these functional groups, the physical and chemical properties of soy-based adhesives can be changed by directional modification
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
