Preparation of phosphorus-containing and nitrogen-containing durable flame retardant polyacrylonitrile fabric via surface chemical modification

摘要

Ultraviolet-induced photografting polymerization combined with surface modification was developed to prepare durable flame retardant polyacrylonitrile (PAN) fabric. First, acrylic acid (AA) was grafted onto PAN fabric (PAN-g-PAA) through ultraviolet-induced photograft polymerization. Then, PAN-g-PAA was modified sequentially by acylation, ammonization, and phosphorylation to obtain acylated PAN-g-PAA, ammoniated Cl-PAN-g-PAA, and fire retardant PAN fabric, respectively. The influence of grafting time, concentration of acrylic acid, and initiator on the grafting percentage was studied in detail. Fourier transform infrared spectrometer, X-ray diffraction, and scanning electron microscopy confirm the successful grafting of AA. The thermal properties of the fabrics were investigated by thermogravimetric analysis and differential scanning calorimetry. Thermal analysis indicates that FR-PAN has good thermal stability at higher temperature and the char residue is about 41 wt% at 800 degrees C. The limiting oxygen index value of the fire retardant fabrics can achieve 28.1 vol% and is still 27.3 vol% after 20 cycles washing, showing good durability.