Date of Award
Fall 12-13-2014
Document Type
Thesis
Degree Name
Master of Science in Chemistry (MSChem)
Department
Chemistry
First Advisor
Dr. Ram K. Gupta
Second Advisor
Dr. Khamis Siam
Third Advisor
Dr. Timothy Dawsey
Keywords
Adhesive
Abstract
Thermomechanical Performance Assessment of Bio-based PU Adhesives Derived from Castor Oil
An Abstract of the Thesis by
Anand V. Patel
Adhesives play a critical role in binding diverse materials, thereby promoting structural integrity and functional versatility across numerous daily applications. A significant challenge remains in developing polyurethane adhesives that exhibit exceptional bonding strength, as many are derived from petroleum products. To reduce dependence on non-renewable resources and offer sustainable and affordable alternatives, vegetable oils are being utilized to create a range of polyurethane adhesives. These oils are preferred due to their low toxicity, cost-effectiveness, and reduced environmental impact. This research uses castor oil, a non-edible oil with inherent hydroxyl functionality, to prepare polyurethane-based adhesives. This study synthesizes two distinct polyols derived from castor oil (CO) : CO-based polyol (COP) and hyperbranched CO polyol (CO20). These polyols are differentiated by their specific chemical modifications, and resulting molecular structures confer unique properties and applications.
Polyurethane-based adhesives were prepared using CO, COP, and CO20. The reaction depends primarily on the properties of the polyol and isocyanates, with the hydroxyl number of the polyol being a key factor influencing the crosslinking and bonding strength of the adhesives. To enhance the hydroxy value by ring-opening reaction in COP and by stoichiometry reaction in CO20, then improve the chemical and mechanical properties of the adhesives, the CO adhesive sample cured at 60°C demonstrated the highest bonding strength of 3.7 MPa compared to other CO samples. The COP and CO20 adhesive samples, which have higher hydroxyl values compared to CO, achieved higher tensile strengths, with COP reaching 5.7 MPa and CO20 attaining 5.8 MPa at room temperature. Among all samples, CO20 consistently exhibited the highest Tg at every cured temperature, while COP showed higher Tg than the CO adhesive sample at all curing temperatures. This research provides sustainable alternatives to petroleum-based adhesives with superior thermal and mechanical properties.
Recommended Citation
PATEL, ANAND, "Thermomechanical Performance Assessment of Bio-based PU Adhesives Derived from Castor Oil" (2014). Electronic Theses & Dissertations. 825.
https://digitalcommons.pittstate.edu/etd/825
