Cellulose-Based Polyurethane Foams of Low Flammability

Area of Science:

• Materials Science
• Polymer Chemistry
• Sustainable Chemistry

Background:

• Decreasing oil resources necessitate bio-based alternatives for polyurethane foam (PUF) production.
• Cellulose is a promising, low-cost biopolymer, but its low reactivity limits its use in polyol synthesis.
• Previous cellulose-derived polyols resulted in flammable biodegradable rigid PUFs.

Purpose of the Study:

• To develop flame-retardant biodegradable rigid polyurethane foams (PUFs) from cellulose.
• To synthesize a novel cellulose-based polyol using a reactive flame retardant.
• To evaluate the flammability and properties of the modified PUFs.

Main Methods:

• Synthesized a cellulose-based polyol incorporating a diethylene glycol and phosphoric(III) acid ester as a reactive flame retardant.
• Characterized the polyol using infrared spectra (IR) and proton nuclear magnetic resonance (¹H-NMR).
• Formulated and produced rigid PUFs with the modified polyol and melamine as an additive flame retardant, testing various physical and thermal properties, including flammability via oxygen index, horizontal flammability, and calorimetric analysis.

Main Results:

• The cellulose-based polyol was successfully synthesized and characterized.
• The modified rigid PUFs exhibited improved flammability resistance compared to non-modified and classic PUFs.
• Key properties such as density, viscosity, hydroxyl numbers, water uptake, dimensional stability, and compressive strength were determined for the PUFs.

Conclusions:

• The developed cellulose-based polyol and modified rigid PUFs offer a viable route to sustainable and safer materials.
• The incorporation of a reactive flame retardant significantly enhances the fire safety of biodegradable PUFs.
• This research contributes to the development of eco-friendly materials with reduced flammability for broader applications.