Synthesis and characterization of new insensitive and high-energy dense cellulosic biopolymers

In the present study, microcrystalline cellulose carbamate nitrate (MCCCN) and ordinary cellulose carbamate nitrate (OCCN) as a new class of insensitive and high-energy dense polymers were successfully synthesized for the first time through a simple efficient procedure. Carbamate-functionalized cellulose and cellulose microcrystals (OCC and MCCC) were firstly prepared from their precursors using chlorosulfonyl isocyanate (CSI) as carbamate agent. After that, the nitration of functionalized and non-functionalized cellulosic precursors with concentrated sulfonitric mixtures was undertaken. Their physico-chemical features, molecular structure, thermal behavior, and mechanical sensitivity features were determined, and compared to those of the common nitrocellulose and emergent microcrystalline cellulose nitrate (OCN and MCCN). Furthermore, the detonation properties of the developed energetic polymers were evaluated using Explo5 (V6.04) computer code. The findings of this study confirm the efficiency of the performed surface modification approach to produce insensitive MCCCN and OCCN with excellent features such as density of 1.687 g/cm3 and 1.703 g/cm3, explosion energy of 5040 kJ/ kg and 5334 kJ/kg, and detonation velocity of 7613 m/s and 7785 m/s, respectively, which are better than those of the conventional nitrocellulose. This work provides a novel and sustainable pathway to prepare new insensitive energetic polymers with outstanding physicochemical properties and energetic performances from renewable cellulose, which may further promote the functional application of cellulose and open the way of cellulose-based energetic materials for explosive formulations and high-performance propellants.

Automated summary

In this study, microcrystalline cellulose carbamate nitrate (MCCCN) and ordinary cellulose carbamate nitrate (OCCN) were successfully synthesized as insensitive and high-energy dense polymers for the first time. The efficient surface modification approach used in the study produced MCCCN and OCCN with excellent features such as high density, explosion energy, and detonation velocity, which outperformed conventional nitrocellulose. This work provides a novel pathway for preparing insensitive energetic polymers from renewable cellulose, further promoting the functional application of cellulose-based energetic materials.