A novel reaction mechanism for the synthesis of coconut oil-derived biopolyol for rigid poly(urethane-urea) hybrid foam application

Roger G Dingcong Jr; Roberto M Malaluan; Arnold C Alguno; Dave Joseph E Estrada; Alona A Lubguban; Eleazer P Resurreccion; Gerard G Dumancas; Harith H Al-Moameri; Arnold A Lubguban

doi:10.1039/d2ra06776e

A novel reaction mechanism for the synthesis of coconut oil-derived biopolyol for rigid poly(urethane-urea) hybrid foam application

RSC Adv. 2023 Jan 11;13(3):1985-1994. doi: 10.1039/d2ra06776e. eCollection 2023 Jan 6.

Authors

Affiliations

¹ Center for Sustainable Polymers, Mindanao State University - Iligan Institute of Technology Iligan City 9200 Philippines arnold.lubguban@g.msuiit.edu.ph.
² Department of Chemical Engineering and Technology, Mindanao State University - Iligan Institute of Technology Iligan City 9200 Philippines.
³ Department of Mathematics, Statistics, and Computer Studies, University of the Philippines Rural High School Paciano Rizal, Bay Laguna 4033 Philippines.
⁴ Civil Engineering Technology, Montana State University-Northern Havre MT 59501 USA.
⁵ Department of Chemistry, The University of Scranton Scranton PA 18510 USA.
⁶ Materials Engineering Department, Mustansiriyah University Baghdad 10052 Iraq.

Abstract

Coconut oil (CO) has become one of the most important renewable raw materials for polyol synthesis due to its abundance and low price. However, the saturated chemical structure of CO limits its capability for functionalization. In this study, a novel reaction mechanism via the sequential glycerolysis and amidation of CO triglycerides produced an amine-based polyol (p-CDEA). The synthesized biopolyol has a relatively higher hydroxyl value of 361 mg KOH per g relative to previously reported CO-based polyols with values ranging from 270-333 mg KOH per g. This primary hydroxyl-rich p-CDEA was used directly as a sole B-side polyol component in a polyurethane-forming reaction, without further purification. Results showed that a high-performance poly(urethane-urea) (PUA) hybrid foam was successfully produced. It has a compressive strength of 226 kPa and thermal conductivity of 23.2 mW (m^-1 K^-1), classified as type 1 for a rigid structural sandwich panel core and type 2 for rigid thermal insulation foam applications according to ASTM standards. Fourier-transform infrared (FTIR) spectroscopy was performed to characterize the chemical features of the polyols and foams. Scanning electron microscopy (SEM) analysis was also performed to evaluate the morphological structures of the synthesized foams. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were conducted to investigate the foam's thermal characteristics. Thus far, this work is the first to report a novel and effective reaction mechanism for the synthesis of a highly functional CO-derived polyol and the first CO-based polyol with no petroleum-based replacement that may serve as raw material for rigid PUA foam production. PUA hybrid foams are potential insulation and structural materials. This study further provided a compelling case for enhanced sustainability of p-CDEA PUA hybrid foam against petroleum-based polyurethane.