Obtención y caracterización de carbamato de celulosa como alternativa de disolución al proceso de viscosa

Abstract

The chemical functionalization of natural polymers constitutes a viable approach for sustainable development, being also a technologically and economically attractive alternative. At present, the viscose process continues being the form of cellulose esterification and dissolution more used by the industry, in spite of the pollution caused by the use of carbon disulfide. Within this framework, it was proposed the obtaining of cellulose carbamate as an alternative to the viscose process, using a different methodology with respect to conventional processes that include treatments with aqueous or gaseous ammonia, very high temperatures and long reaction times, among others. The preparation of cellulose carbamate from mixtures of urea and eucalyptus dissolving pulp activated with alkali was effective through microwave heating. On the other hand, mechanical and enzymatic treatments were applied to the dissolving pulp, with the aim of improving its accessibility and reactivity. These pretreatments allowed the obtaining of viscose solutions with 40 % less of carbon disulfide and without the aging stage where the required depolymerization of the working pulp occurs. In addition, these solutions with cellulose concentrations less than or equal to 6 % showed a different rheological response to the typical

La funcionalización química de polímeros naturales constituye un enfoque viable para el desarrollo sustentable, siendo además una alternativa tecnológica y económicamente atractiva. En la actualidad, el proceso de viscosa continúa siendo la forma de esterificación y disolución de celulosa más utilizada por la industria, a pesar de la polución causada por el uso de sulfuro de carbono.