STUDY OF AN ARAMID SURFACE REACTIVITY - MODIFICATION WITH A COLD-PLASMA OR AN ELECTRON-BEAM FOLLOWED BY A POSTGRAFTING REACTION

Different modes of activation are described for a postgrafting reactio n of acrylic acid on poly(p-phenylene terephthalamid) (PPTA):nitrogen plasma or electron-beam irradiation. Both lead to surface radical form ation, and these species are able to initiate grafting. The functional ization through amino group attachment is characteristic of plasma tre atment. Degradation initiated by UV-visible emission of plasma is noti ced, leading to the amide clivage. The surface grafting is more import ant when the PPTA is irradiated with a cold plasma and if water is use d as the solvent. The polymer crystallinity degree reduces the graftin g of the electron beam-irradiated PPTA even with a high radical concen tration. (C) 1994 John Wiley & Sons, Inc.