Phosphorous-Based, Halogen-Free Flame Retardants for Thin, Flexible Polyurethane Artificial Leathers.

Area of Science:

• Materials Science
• Polymer Chemistry
• Fire Safety Engineering

Background:

• Polyurethane (PUR) artificial leathers are widely used in public interiors, necessitating effective flame retardants (FRs).
• Standard FRs designed for bulk PUR materials are often less effective in thin films and artificial leathers.
• There is a need for halogen-free FRs to replace environmentally harmful and health-damaging alternatives.

Purpose of the Study:

• To evaluate the efficacy of twelve commercially available, halogen-free FRs in PUR films and artificial leathers.
• To identify the most suitable FRs for enhancing the flame resistance of thin PUR materials.
• To investigate potential synergistic effects between different FRs and additives.

Main Methods:

• Incorporation of twelve halogen-free FRs into PUR films and artificial leathers at various concentrations and combinations.
• Assessment of fire resistance using Limiting Oxygen Index (LOI) measurements, cone calorimetry, horizontal burning tests, and thermogravimetric analysis (TGA).

Main Results:

• An organophosphorus FR demonstrated superior performance, increasing LOI from 20 to 24.2%, reducing peak heat release rate by approximately 30%, and achieving self-extinguishing behavior.
• Phosphinates and aluminum trihydroxide showed limited efficiency as flame retardants for these materials.
• Combinations of bentonite with phosphorus-based FRs exhibited synergistic effects, reducing ignitability.

Conclusions:

• Commercially available halogen-free FRs can effectively impart flame retardancy to thin PUR-based materials.
• Organophosphorus FRs are particularly promising for flame-resistant artificial leather applications.
• This research supports the development of more sustainable and safer materials by replacing hazardous FRs.