Preparation of oxycellulose from medical cotton and gauze using tempo oxidizer

• Main Authors: Валерій Анатолійович Барбаш, Тетяна Володимирівна Зеленчук, Ірина Михайлівна Дейкун, Анна Сергіївна Гондовська
• Format: Article
• Language: English
• Published: Igor Sikorsky Kyiv Polytechnic Institute 2020-07-01
• Series: Вісник Національного технічного університету України «Київський політехнічний інститут імені Ігоря Сікорського»: Серія «Хімічна інженерія, екологія та ресурсозбереження»
• Subjects: вата; марля; окиснення; темпо; оксицелюлоза
• Online Access: http://chemengine.kpi.ua/article/view/208056
• ISSN: 2617-9741; 2664-1763

Today there is a steady increase in the use of renewable biological resources for chemical processing. Obtaining hemostatic materials based on oxycellulose, which can be adsorbed in living tissues, is an urgent scientific and practical task. Medical hygroscopic non-sterile cotton wool made of long-fiber cotton fiber of industrial production and non-sterile gauze bandage were used for the experiments. Oxidation of medical cotton wool and gauze fibers was performed with TEMPO solutions with consumption from 0.5% to 10% by weight of absolutely dry raw materials, with the addition of 0.12 g of NaBr and from 5 to 10 cm3 of sodium hypochlorite solution with a concentration of active chlorine of 76 g/dm3, temperature from 20 to 60 oC and the duration of the process from 2 to 48 hours. The chemical composition of medical cotton wool and gauze have an α-cellulose content of more than 98%, as well as a low content of non-cellulose impurities and can be used for the oxidation process. The influence of technological parameters - temperature, duration of oxidation process, consumption of TEMPO and sodium hypochlorite on the quality of oxycellulose from fibers of medical cotton wool and gauze is established. The increase in the consumption of the oxidazer TEMPO and the duration of the oxidation process leads to an increase in the content of carboxyl groups to 4.5% and 5.0% in the obtained samples of oxycellulose from cotton wool and gauze, respectively. Increasing the consumption of sodium hypochlorite helps to increase the content of carboxyl groups in the obtained samples of oxycellulose, but also reduces the yield of oxycellulose due to its destruction. Increasing the temperature of the oxidation process from 20 oC to 40 oC promotes an increase in the number of carboxyl groups, and when the temperature rises to 60 oC there is a partial destruction of cellulose fibers. The yield of oxycellulose decreases with increasing oxidant consumption and increasing process temperature. The highest yield of oxycellulose was observed in medical gauze, because it is more tightly bound fibers, which prevents the process of its destruction. The change of the amount of amorphous and crystalline parts of cellulose of cotton fibers in the oxidation process was determined by the X - ray diffraction method. The oxidation process helps to reduce the content of amorphous parts of cellulose of cotton fibers due to its destruction under the action of oxidants. Medical gauze and cotton wool, oxycellulose from gauze and cotton wool had values of the crystallinity index of 86.5%, 85.7%, 90.0% and 90.9%, respectively. It is recommended to carry out the process of oxidation of cotton pulp to obtain oxycellulose from medical cotton wool and gauze with the maximum content of carboxyl groups at a consumption of TEMPO from 5% to 10% by weight a.s.s., temperature 20 °C for 24 - 48 hours.