Abstract
The thermo-oxidative atability (i.e. the retension of warp tensile strength of fabric after heat exposure at 130°C for a long duration) of acrylic acid grafted nylon 6 fabrics, treated with some metallic salts or tris (1-aziridinyl) phosphine oxide (APO), was studied.
The results obtained were different in some aspects from those of polypropylene fabrics reported previously. The thermo-oxidative stability of nylon 6 fabric was improved to some extent by the grafting of acrylic acid. The conversion of carboxylic groups in the grafted nylon 6 fabrics to a metallic salt-form was carried out with aqueous solutions of metallic salts. When calcium, chromium or nickel salts were used, the metallization was more or less effective on the stability of fabrics, but the effects were not so remarkable as in the case of the grafted polypropylene. The stability in copper salt-form was deteriorated somewhat by heat, but the extent of the damage was not so significant as in the case of acrylic acid grafted polypropylene. The fact that the grafting and the subsequent chromium salt formation improve the stability of nylon 6 fabrics but rather spoil the stability of polypropylene may suggests that some differences are present between the mechanisms of thermo-oxidative degradation of the two polymers, although a similar radical mechanisms have been assumed. The treatment with APO, which imparted a better stability to acrylic acid grafted polypropylene fabrics, was also effective for ungrafted nylon 6 fabric but was not for the grafted nylon 6 fabrics, since the addon of APO attained was small.
