carried out with sps and mbs catalysers well known by a person skilled in the art the precursor polymer thus obtained shows a viscosity of 5500 cps lv3 12 rpm the hofman degradation itself is carried out in the same manner as in example 1 of the patent of the applicant pct fr 2009 050456 the acrylamide derivative copolymer a thus obtained shows an intrinsic viscosity of 0 72 25 u00b0 c brookfield lv1 60 rpm and a concentration of 8 a 1 1 ratio of a knit cotton viscose 50 50 of 150 g m 2 is degreased in a winch the bath ratio is 1 25 1g l of a wetting detergent is added to the bath the bath is then heated and maintained at 60 u00b0 c for 25 minutes the bath is then emptied and the material is then rinsed twice using cold water at 15 u00b0 c the pre treatment is then carried out with a bath ratio of 1 25 the ph is adjusted at 9 with sodium carbonate and 5 in weight of polymer a material is added the bath is heated and maintained at 60 u00b0 c for 30 minutes the bath is emptied and the material is then rinsed twice using cold water at 15 u00b0 c the.