Improving Polyurethane Adhesives through Schiff Base Crosslinkers: A Sustainable Approach Using Soybean Oil
Category
Sciences and Technology
Department
Material Science
Student Status
Graduate
Research Advisor
Dr. Ram K. Gupta
Document Type
Event
Location
Governors
Start Date
10-4-2025 11:40 AM
End Date
10-4-2025 12:00 PM
Description
Historically, polyurethanes (PUs) have typically been made using petroleum-based polyols such as urea or phenol formaldehyde, both of which pose risks to human health and harm the environment. As a result, sectors have recently expressed interest in developing bio-based PUs made from polyol sourced from vegetable oil and diisocyanate. In this study, PU-based adhesives are developed using soybean oil polyol (SOP) and methylene diphenyl diisocyanate. To improve the performance of the synthesized PU adhesive, Schiff-based diols designated as VB and VH have been added to the system as crosslinkers, derived from butane diamine, hexane diamine, and vanillin. The successful creation of PU has been confirmed using Fourier transform infrared spectroscopy (FT-IR) spectra. The tensile strength of adhesive samples was tested on oak wood specimens. Among adhesive samples using VB, VB-10wt.% demonstrated the highest tensile strength at 4400 KPa when compared to all other weight percentages (wt.%). In contrast, VH-based adhesive samples recorded their maximum tensile strength for VH-10wt.% at 5000 KPa. In both cases, as the wt.% of Schiff base diol increases, the tensile strength decreases to 3800 KPa for VB-15wt.% and 2900 KPa for VH-15wt.%. Furthermore, the produced PU adhesive samples demonstrate thermal stability, as confirmed through thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) evaluations. Moreover, the tests for gel content and degree of swelling further illustrate the efficiency of crosslinking in the PU adhesive materials.
Improving Polyurethane Adhesives through Schiff Base Crosslinkers: A Sustainable Approach Using Soybean Oil
Governors
Historically, polyurethanes (PUs) have typically been made using petroleum-based polyols such as urea or phenol formaldehyde, both of which pose risks to human health and harm the environment. As a result, sectors have recently expressed interest in developing bio-based PUs made from polyol sourced from vegetable oil and diisocyanate. In this study, PU-based adhesives are developed using soybean oil polyol (SOP) and methylene diphenyl diisocyanate. To improve the performance of the synthesized PU adhesive, Schiff-based diols designated as VB and VH have been added to the system as crosslinkers, derived from butane diamine, hexane diamine, and vanillin. The successful creation of PU has been confirmed using Fourier transform infrared spectroscopy (FT-IR) spectra. The tensile strength of adhesive samples was tested on oak wood specimens. Among adhesive samples using VB, VB-10wt.% demonstrated the highest tensile strength at 4400 KPa when compared to all other weight percentages (wt.%). In contrast, VH-based adhesive samples recorded their maximum tensile strength for VH-10wt.% at 5000 KPa. In both cases, as the wt.% of Schiff base diol increases, the tensile strength decreases to 3800 KPa for VB-15wt.% and 2900 KPa for VH-15wt.%. Furthermore, the produced PU adhesive samples demonstrate thermal stability, as confirmed through thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) evaluations. Moreover, the tests for gel content and degree of swelling further illustrate the efficiency of crosslinking in the PU adhesive materials.
