Synthesis of new cellulose derivatives—XXIV. Synthesis of a cellulose-polyacrylonitrile graft copolymer and investigation of its properties☆

THE synthesis of graft copolymers of cellulose with carbon-chain polymers without the simultaneous formation of homopolymer [1] makes possible the production of various modified celluloses possessing new properties of practical value. One of the most interesting and promising materials obtained by graft polymerization on to cellulose, in particular on to cotton and viscose fabrics, must be the graft copolymer of cellulose and polyacrylonitrile. The possibility of carrying out the grafti:lg p?ocess by using an aqueous solution Of AN without subsequent washing out of the homopolymer considerably simplifies the practical application of this method. I t may be expected that the specific valuable properties of polyaerylonitrile (PAN) grafted to cellulose should improve the properties of the modified cellulosic material . Therefore it was considered desirable to carry out the grafting of PAN to cellulose fabric or fibre and to investigate the change caused by grafting in some of the properties of these materials which are valuable in practice. An investigation of the influence of the number and size of the grafted PAN chains on the properties of the material obtained also has great scientific and practical interest. With the same amount of grafted polymer, its distribution in side chains may vary widely. Thus, for example, the grafting Of PAN on to cellulose may give modified celluloses containing the same amour of nitrogen, i.e. the same amount of grafted PAN, while one of them may contain a small number of long PAN side chains and the other a large number of short chains. I t is apparent that the behaviour of such materials in respect of a number of practically important characteristics will be different. Since there is no information in the literature on this question, we considered it desirable to a t tempt to s tudy the change in the properties of a graft eopolymer of cellulose and PAN not only in respect of the amount of grafted polymer but also in respect to the nature of the distribution of the grafted polymer (the number and size of the side chains). The results obtained are given in the presen~ paper.