Microwave assisted preparation of self-extinguishing cotton fabrics by small molecules containing phosphorous and nitrogen

Authors: Chang, Sechin; Condon, Brian; Smith, Jade

Submitted to: Current Microwave Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/24/2019
Publication Date: 3/1/2019
Citation: Chang, S., Condon, B., Smith, J. 2019. Microwave assisted preparation of self-extinguishing cotton fabrics by small molecules containing phosphorous and nitrogen. Current Microwave Chemistry. 6:1-10. https://doi.org/10.2174/2213335606666190301160053.
DOI: https://doi.org/10.2174/2213335606666190301160053

Interpretive Summary: Flame retardant (FR) finishing treatments based on phosphorous and nitrogen containing small molecules have been applied to cotton fabrics using microwave-assisted technology. The FR treated fabrics produced a higher carbonaceous residue when compared with untreated fabric. In conclusion, both piperazine based phosphoramidate derivatives are promising flame retardants for applications to cotton textiles, but the flame retardancy by the burning rate and the heat of combustion and the char yield. We have developed an efficient microwave assisted method for fabric treatment which has the advantages of shorter reaction time and simple procedure. Overall, our results expose that most of the flame retardant treated fabrics showed better anti-flammable activity than the control fabric.

Technical Abstract: New methods for preparing surface modification of flame retardant cotton fabrics were employed by applying a microwave-assisted technique with a minimum amount of co-solvent. Our efforts at flame retardant cotton fabrics treated with economic and environmentally friendly flame retardant compounds based on small molecules based on piperazine, PN and PNN, were done successfully. The evidence of flame retardant chemical penetrations or surface modification of cotton fabrics was confirmed by scanning electron microscope (SEM), and the treated cotton fabrics were evaluated by flammability tests, such as 45°angle (clothing textiles test) and limiting oxygen index (LOI). Thermogravimetric analysis of the treated cotton fabrics in a nitrogen atmosphere showed that decomposition occurred between 276.9~291.2°C with 30.5~35.7% residue weight char yield at 600°C, indicating high thermal stability for all treated levels. Limiting oxygen index (LOI) and the 45° angle flammability test were employed to determine the effectiveness of the flame-retardant treatments on the fabrics. LOI values increased from ~18 vol% oxygen in nitrogen for untreated fabric to a maximum of 32 vol% for the highest treatment level. Fabrics with higher levels of flame retardant also easily passed the 45° angle flammability test. In the Microscale combustion calorimeter (MCC) tests, the smaller values obtained for THR, HRC and Tmax for all PN and PNN samples showed a better reduction in heat of combustion.