Investigation of thermal and optical properties of waste newspaper with bacterial cellulose and borax additives

Abstract

Due to decreasing forest resources and increasing environmental problems, alternative cellulose sources have been researched, studies are being carried out on the use of non-woody or recycled fiber sources in paper production. The production and consumption amounts of paper and paper products produced from waste paper and their variety increase every year. As an alternative source of cellulose, bacterial cellulose (BS), produced by biosynthesis from various microorganisms, is very interesting due to its superior properties. In this study, the effects of BS additive as a reinforcement to the recycled waste newspaper and the borax pentahydrate (Na2B4O7.5H2O), applied to retard the burning property of the paper, on the thermal and optical properties of the produced papers were investigated. The immersed method was chosen for the borax application and the addition of borax during production was also studied in order to make comparison. In order to determine the burning characteristics and kinetics of the papers, their thermal properties were determined. Brightness, yellowness and color values (L*, a*, b*) were determined for optical properties. When the TGA data were evaluated, it was determined that the inflection point temperature decreased from 377.53°C to 335.55°C as a result of borax application with immersion method and it increased slightly to 379.53°C with only BS additive. It was determined that the inflection point temperature of BS reinforced papers decreased to 334.24°C as a result of borax application with immersion method and it gave the highest residual amount at 590°C with a rate of 44.03% compared to other samples. As a result, the thermal resistance of BS reinforced papers with borax application with immersed method is better than the other samples. BS and borax reduce the formation of calories during the burning of the paper, thus this ends the burning quickly. In terms of optical properties, it was found that BS reinforcement and borax application reduce the brightness value and increase the yellowness of the paper.