Green Polymer Approach in the Production of Polyurethane Foams Using Chitosan and Citric Acid-Based Polyols

Area of Science:

• Materials Science
• Polymer Chemistry
• Sustainable Chemistry

Background:

• Polyurethane (PU) foams derived from fossil fuels present environmental and economic concerns.
• Developing sustainable alternatives for PU production is a key research area.
• Chitosan, a biopolymer, is explored as a potential eco-friendly substitute for fossil-based polyols.

Purpose of the Study:

• To investigate the feasibility of using chitosan as a bio-based polyol in PU foam synthesis.
• To develop an efficient and environmentally friendly method for chitosan liquefaction.
• To characterize the properties of PU foams produced with chitosan-based biopolyols.

Main Methods:

• Chitosan was liquefied using citric acid, forming a novel biopolyol.
• Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) and Fourier-transform infrared (FTIR) spectroscopy confirmed esterification.
• The biopolyol replaced 50% of fossil-based polyether polyol in PU foam synthesis.
• Characterization included FTIR, scanning electron microscopy (SEM), compressive strength tests, and thermogravimetric analysis (TGA).

Main Results:

• Successful liquefaction of chitosan with citric acid via esterification was achieved.
• PU foams incorporating the chitosan-based biopolyol exhibited enhanced thermal stability, with maximum decomposition temperature increasing from 390 °C to 429 °C.
• The study confirmed the chemical structure, morphology, and mechanical properties of the novel PU foams.

Conclusions:

• The liquefaction of chitosan with citric acid provides a novel, cost-effective, and sustainable route to bio-based polyols.
• This method offers an environmentally friendly and economically viable alternative for producing enhanced polyurethane foams.
• The findings represent a significant advancement in sustainable polymer chemistry and materials science.