SOME PRELIMINARY STUDIES OF THE THERMAL-BEHAVIOR OF ELECTRON-BEAM GRAFTED POLYAMIDES

Attempts are being made by this group to improve the thermal character istics of a polyamide based material commonly used in the textile indu stry. Study has been made of the use of accelerated electron beams for the induced grafting of acrylic and methacrylic acids onto sheets of polyamide fibres. Samples of polyamide, in the form of rectangular she ets of dimensions 10 cm x 10 cm, have been irradiated using a 3 GHz tr avelling wave electron accelerator of energy 6 MeV; the source incorpo rates a 0.1 mm Al foil exit window. Results show that the degree of gr afting displays a number of critical dependencies, including irradiati on dose and extent of monomer dilution. Application of the technique o f differential scanning calorimetry to the study of these modified mat erials has indicated there to be a well-correlated association between increase in the degree of grafting and decrease in the softening rate of the modified polyamide as the melting temperature of the material is approached. Flame tests reveal that the greater the degree of graft ing, the greater the similarity of the burning pattern of cellulosic m aterials, cotton, paper, etc. The decrease in signal magnitude and occ asional disappearance of exothermic peaks for moderate degrees of graf ting encourages this group to continue investigation of favourable mod ification of thermal behaviour of polyamide based materials through us e of accelerated electron beam induced grafting. (C) 1997 Elsevier Sci ence Ltd. All rights reserved.