Date of Award
Spring 5-15-2024
Document Type
Thesis
Department
Chemistry
First Advisor
Dr. Ram K. Gupta, (rgupta@pittstate.edu)
Second Advisor
Dr. Khamis Siam, (ksiam@pittstate.edu)
Third Advisor
Dr. Timothy Dawsey, (tdawsey@pittstate.edu)
Keywords
Biobased Adhesive
Abstract
The development of low-cost bio-based formaldehyde-free adhesives has aroused widespread interest in the adhesive industry. The usage of adhesives that contain urea-formaldehyde or phenol formaldehyde leads to environmental issues. Traditional polyurethane adhesives were based on fossil fuels and the use of solvents made them toxic. Petrochemicals are non-renewable resources that will be depleted soon. Therefore, non-renewable materials should be replaced by bio-based renewable resources. Using renewable bio-resources, especially plant oils, as a substitute for petroleum-based polyols is an approach that showed promise. Here, in this research work, soybean oil polyol (SOP) was used to synthesize polyurethane (PU) adhesive. For studying bonding strength, three different aliphatic diols: ethane-1,2-diol (EDO), 1,4-butanediol (BDO), and 1,6-hexanediol (HDO) with increasing chain length were used as a crosslinking reagent. For studying bonding strength, different wt.% of diols were used to synthesize PU adhesives. The bonding strength of these PU adhesives was observed on three different coupons (oak wood, maple wood, and stainless steel). Interestingly, on oak wood, the bonding strength was increased from 3 MPa to 6.36 MPa after incorporating 10 wt.% of BDO which is the highest bonding strength among all the other adhesive samples. In addition, on maple wood, the bonding strength was observed at 4.47 MPa to 7.79 MPa after adding 7.5 wt.% of HDO crosslinker in PU adhesive. Thermal properties of the synthesized adhesive were studied. A solubility test was also performed to check the solvent's effect on these PU adhesives and the degree of crosslinking. After being immersed in different solvents for 24 hours, there were no notable changes observed in the FT-IR spectra of these PU materials. Contact angle of these adhesives was above 90˚ confirming the hydrophobic nature. This work provides a sustainable alternative to petroleum-based adhesives with good bonding and physical properties without using solvents and catalysts.
Recommended Citation
Parekh, Sonu, "A SOLVENT AND CATALYST-FREE APPROACH FOR SYNTHESIZING BIO-BASED ADHESIVE USING VARIOUS DIOLS" (2024). Electronic Theses & Dissertations. 519.
https://digitalcommons.pittstate.edu/etd/519
