A new process for producing of commercial nitrocellulose with chipping technology of sheet wood pulp

Nitrocellulose is one of the most important cellulose derivatives used in industry and commerce and one of the most important products of the chemical industry. Nitrocellulose is produced using the raw material alpha cellulose such as cotton linters pulp or dissolving wood pulp. For both raw materials, the appropriate form should be "fluff" or "mass", which is used in the form of fluffy bales for cotton linters, and in the form of wood pulp, which is used in the form of sheets, which are first fluffed in a hammer mill and then nitrated. The aim of this research is to use a new method to reduce the size of wood pulp sheet. Then nitrated and produce commercial Nitrocellulose. In this study, an attempt is made to convert dense wood pulp sheets with a purity level of approximately 90% into chips and to produce Nitrocellulose by using a semi-industrial chopper, and finally to investigate the quality of the Nitrocellulose such as nitrogen percent, solubility, fineness, viscosity, thermal stability and resulted lacquer specification in terms of, turbidity, softness, color and transparency. In this study, the sheets were crushed and chipped using a chopper with pore size of 3 cm × 3 cm, 2.5 cm × 2.5 cm, 2 cm × 2 cm, 1.5 cm × 1.5 cm and 1 cm × 1 cm. Then, the chips were nitrated, separated additional acid boiled, milled and finally washed. The results showed that chips with a size of 3 cm × 3 cm are nitrated at the outer edges while no nitration occurs in the core and center of the chips. Reducing the size of the chips, the penetration of the chips improves, so that the best acid absorption can be observed with 1 cm × 1 cm chip. However, the main problem is that the amount of dust increases and the passing of fine particles through the filter increases. As a result, production yield decreases. Finally, the best pore size for chip production is 1.5 cm × 1.5 cm, which both increases the Capacity of chip production and enables better nitrating, and the passing of particles through the pores of the filter is very low. Thus, in this case, there are very few unnitrated particles, a lacquer turbidity of 11, appropriate softness, reasonable Bergmann stability of maximum 1.4 mgr., alkalinity of 0.01, acetone insolubility of 0.11 percent, and very few physical impurities. Also, the acid to cellulose ratio was reduced from 65/1 to 30/1 in the nitrator and from 25/1 to 15/1 in the autoclave compared to the fibrous state. Finally, the FT-IR graph shows that Nitrocellulose from the best chips exhibits a peak corresponding to the NO₂ functional group and a peak corresponding to the OH functional group, which is very similar to those of Nitrocellulose from alpha cellulose cotton fiber. In GPC test average molecular weight Nitrocellulose resulted best chips (1.5 cm × 1.5 cm) was 55,303 Dalton and for Nitrocellulose produce from cotton linter pulp was 59,402 Dalton. The DSC showed that exothermic peak resulted of decomposition of Nitrocellulose from the best chips exhibits a peak in 202 °C which is very similar to those of Nitrocellulose from alpha cellulose cotton fiber (201 °C).