Abstract
For the purpose of making polyester fiber flame retardant, experiments to incorporate chlorine atoms in poly (ethylene terephthalate) were undertaken by radiation-induced chlorination.
Filament or fabric of the polyester was placed in a glass reaction vessel in which chlorine gas was filled to atmospheric pressure and irradiated by γ-rays at room temperature. After irradiation of 20h at a dose rate of 5.6×104 rad/h, the chlorine contents were 6.2 and 4.8% for the filament and the fabric respectively. Further irradiation increased the chlorine content only a little. The initial G-value of the chlorination for the filament was calculated to be 3.8×104 When the polyester was impregnated with a suitable swelling agent and subjected to the chlorination, the reaction proceeded more rapidly.
The fibers with over 20% chlorine content were prepared by repeated filling of fresh chlorine and irradiation.
Tenacity of fibers decreased slightly by the chlorination; 4.9g/d of the original fiber to 3.5g/d for 13.7% chlorination. Although flame-retardance of the fiber was much improved by the chlorination, the thermal stability of the chlorinated fiber tested by a thermogravimetric analysis was inferior to that of the original fiber.
