IMPROVED RESISTANCE TO FLAMMABILITY OF AROMATIC POLYAMIDE FIBERS BY HALOGEN AND PHOSPHORUS CONTAINING POLYMERS

Aromatic polyamide fibers were modified by phosphorous and halogen compounds and their flammability and related properties were examined.Because of the good durability and reproducibility, we adopted the method of blending. In order to evaluate the flammability of fibers and fabrics, we have established a Limiting Oxygen Index test ignited from the bottom of samples (LOI-B), in addition to the standard method in which the samples were ignited from the top (LOI-T). Mechanical resistances to very hot flame and iron were also estimated. The following results were obtained.1) Flame-retardant Halogen compounds increased the LOI-T value but not the LOI-B one. Phosphorous compounds were found to be effective for the flammability and especially aliphatic phosphonate was superior to others.2) Flammability By the addition of 1 wt.% Phosphorous to wholly aromatic polyamide, the values of LOI-T and LOI-B became 38.0 and 26_??_27, respectively and mechanical resistances to very hot flame and iron were also greatly improved.3) Spinning Modified polyamide containing 10 wt. % polyphosphonate could be spun in an ordinary way and the properties of fibers such as tenacity and elongation were well good enough for garments.4) Durability After 20 times home washing, phosphorous content did not decrease and the flammabilities were maintained.