الفهرس | Only 14 pages are availabe for public view |
Abstract The Egyptian’ raw hides and skins are considered to be among the best in the world since they have a very smooth grain surface with no injuries, bruises or cuts and they also have warble fly damages. The aim of this investigation is to prepare a class of chloro¬hydrin reactive dyestuffs and testing their usefulness as dyeing dy¬es for vegetable tanned leather. The investigation begins with a theoretical part including the studies and technological aspects, a survey on the dyeing of leather and the types• of leather dyes. It includes an account on the chemical structure of the skin proteins and amino acilies A brief account on vegetable tannins and, vegetable tannage of leather is included in this investigation. This investigation includes also a brief part on the discovery and development of reactive dyes, epoxide reactive dyes, reacti’on of reactive dyestuffs with proteins (wool). The experimental part begins with the preparation of two reactive residues which are important in the preparation of chlorohydrin reactive dyestuffs. Four new reactive chlorohydrin dyestuffs were prepared in good yields by the usual methods of preparation of dyestuffs, using conventional apparatu~. It was noted that the colour of the new dyes did not differ than that of the original mother dyes. The new dyes were applied on g£latin cubes (2 cm. side) and the ~ercentage lipear diffusion was measured for each new dye and compar- ed with that of the corresponding mother dye. It was found that the ~ercentage linear diffusion of the new dyes was higher than that of the ~riginal direct dyes. The new-dyes and the original direct dyes were applied on ve~et- able tanned hide powder, and nylon (polyami~e)powder. The following esults were obtained; A) The percentage absorption of the reactive dyes on vegetable tan- :ned hide powder was higher than that on the nylon powder • B) The percentage absorption of the reactive new dyes was higher Jthan that of the original direct dyes c) The reactive dye absorbed per unit weight of vegetable tanned hide ’powder was higher than the corresponding direct dye absorbed per unit {weight of vegetable tanned hide powder From the above results it was proved that the H-bond playes an ~mportant role in attachment of dyes with collagen. It was noted that the attachment of the reactive dyes with leather was higher than the t,tachment of the original direct dyes, this was attributed to the resence of chlorine atom whi ch reacted wi tll some side chains in pro- ein fibres. The new dyes and the original direct dyes were allowed to react ’With Mimosa solution, and it was found that a gelatinous precipitate |