電子線を用いるビニルフォスフォネートオリゴマーのグラフト重合によるポリエチレンテレフタレート布の難燃化

抄録

For the purpose of making polyethylene terephthalate (polyester) fabric, flame-retardant grafting of oligomeric vinyl phosphonate was carried out using electron-beams either from a Van de Graaff or a Transformer-Rectifier type accelerator at a dose rate of up to 3.3×10⁶ rad/sec.
The fabric impregnated with a selected amount of oligomer was irradiated for the grafting. In the present report “grafting” means only an apparent one and it is very probable that most of the oligomer is deposited on the surface of the fibers as insoluble polymer due to cross-linking.
When 20% methanol solution of the oligomer was used, an average amount of oligomer take up was about 25% and an add-on by grafting up to 20% was obtained at a dose of 20 Mrad with oligomer utilization higher than 75%.
Flame retardance of the fabric is much improved by the grafting. Limiting oxygen index (LOI) increases from 18.5 of original fabric to 26.0 of the fabric containing 12% phosphorus. The fabric of 10% add-on (phosphorus content 2.2%) was proved to be self-extinguishing when it was exposed to open flame according to a netting basket flame-retardance test. The flame-retardance is obtained at LOI of 23.0.
The graft fabric exhibited much improved anti-static property. At about 3% add-on the frictional electric charge was lowered to the same level as that cotton fabric. Thermal stability of the graft fabric tested by thermogravimetric analysis shows that it is far better than the chlorinated fabrics.
No or a very little change in tensile properties of the fabric was observed upon grafting oligomeric vinyl phosphonate. The graft fabric has an excellent hand.