Self-intumescent polyelectrolyte for flame retardant poly (lactic acid) nonwovens

Xingguo Wang; Wenjia Wang; Shuheng Wang; Yufan Yang; Hongfei Li; Jun Sun; Xiaoyu Gu; Sheng Zhang

doi:10.1016/j.jclepro.2020.124497

Self-intumescent polyelectrolyte for flame retardant poly (lactic acid) nonwovens

J Clean Prod. 2021 Feb 1:282:124497. doi: 10.1016/j.jclepro.2020.124497. Epub 2020 Oct 2.

Authors

Xingguo Wang^{1

2}, Wenjia Wang^{1

2}, Shuheng Wang^{1

2}, Yufan Yang^{1

2}, Hongfei Li^{1

3}, Jun Sun^{1

2}, Xiaoyu Gu^{1

2}, Sheng Zhang^{1

3}

Affiliations

¹ State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, China.
² Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing, 100029, China.
³ Beijing Key Laboratory of Advanced Functional Polymer Composites, Beijing University of Chemical Technology, Beijing, 100029, China.

Abstract

The demand for eco-friendly poly (lactic acid) (PLA) nonwovens grows at a high rate in the past several decades, however, only a little attention has been received for flame retardant PLA nonwoven fabrics. In this work, a novel halogen-free self-intumescent polyelectrolyte tris (hydroxymethyl)-aminomethane polyphosphate (APTris) was synthesized by reacting ammonium polyphosphate with tris (hydroxymethyl) aminomethane, and was then used to improve the fire resistance of PLA nonwovens via a dip-nip process. The flammability characterization indicated the limiting oxygen index value was increased to 30.0% from 18.3%, and the damaged area in the vertical burning test was reduced by about 87.0% by the presence of APTris. The cone calorimeter test results revealed that the peak heat release rate and total heat release of the treated sample were decreased by 41.0% and 28.2% respectively compared with that of the control PLA nonwoven sample. The char residue was increased to 12.3 from 1.7 wt % at 800 °C. It is suggested that the dense char barrier formed at the presence of APTris prevents heat, smoke, and gas transfer, and hence enhance thermal dilatability and flame retardancy of PLA nonwovens. This simple sustainable halogen-free treatment has great potential to produce cleaner commercialized flame-retardant PLA nonwovens.

Keywords: Biopolymer; Flame retardancy; Nonwovens; Poly (lactic acid); Polyelectrolytes.