Arabica Coffee Pulp Cellulose: Isolation, Morphology, and its Capabilities to be Modified into Cellulose Nitrate

Abstract

Cellulose nitrate was a cellulose derivative applied in various applications, from plastics to solid propellants for military ammunition and rocketry. Environmental impact from using cotton linter or wood as a source of cellulose for cellulose nitrate industry promoting attempt to use agricultural waste as an alternative source of cellulose. Utilizing non-wood agricultural waste is also advantageous to reduce waste accumulation and give economical value. However, specific cellulose properties should also considered to achieve optimum cellulose derivation process into cellulose nitrate through nitration reaction. Coffee pulp waste had potential to be used as source of non-wood cellulose for its abundance, considerable fraction of cellulose content, low economical value, and unique cellulose morphology. In this study, the cellulose from the coffee pulp was isolated through sodium hydroxide and hydrogen peroxide bleaching method, which furthermore evaluated in terms of their morphology, physical properties, and its capabilities to be derived into cellulose nitrate. The result showed that coffee pulp cellulose has crystallinity and surface area around 59.63% and 0.5962 m2/g, respectively which is lower than cotton linter, suggesting advantageous properties for nitration reaction. Nitration to coffee pulp-based cellulose resulted in moderate nitrogen content cellulose nitrate which still suitable for non-military application.

Cellulose Nitrates-Blended Composites from Bacterial and Plant-Based Celluloses

“…Following this primary degradation, the CN samples exhibited a minor weight loss of 7-10% as they continued to decompose. It is worth noting that the temperature range of the decomposition onset at 199-203 • C is well-documented in the literature for both classical and alternative CN samples [8,13,15,18,19,31,58].…”

“…OHC was inferior to BC in quality attributes but was characterized by quite high quality values for plant-based cellulose, namely, 93.8% α-cellulose content, 0.8% lignin, 0.8% pentosans, 0.31% ash, and 1450 DP. These high values of quality for OHC are comparable to those of Miscanthus cellulose [11] and higher than those of celluloses from oil palm empty fruit bunch, kenaf fibers [12], coffee pulp [18], giant panda feces, and bitter bamboo stems [19], which were successfully nitrated. The blended cellulose samples had intermediate DP values, comparable to the proportional ratio of BC to OHC.…”

“…Notably, the IR spectra of the cellulose samples do not exhibit The infrared (IR) spectra of the initial cellulose samples (Figure 4a), regardless of their origin, exhibit characteristic functional groups representative of cellulose derived from both bacterial and plant sources. These functional groups include peaks at 3339-3354 cm −1 (O-H stretching), 2895-2898 cm −1 (asymmetric and symmetric stretching of C-H), 1635-1650 cm −1 (O-H bending of absorbed water), 1427-1430 cm −1 (asymmetric bending vibration of CH 2 ), 1162-1163 cm −1 (C-O-C stretching), and 1059-1061 cm −1 (skeletal stretching of C-O and vibration of β-glycosidic linkage of cellulose) [8,15,18,19,[32][33][34]. Notably, the IR spectra of the cellulose samples do not exhibit stretching vibration peaks associated with impurity components, such as aromatic structures of lignin at approximately 1500 cm −1 and hemicelluloses at around 1700 cm −1 .…”

“…oat hulls [15], tobacco stalks [16], pistachio shells [17], Arabica coffee pulp [18], giant panda feces, bitter bamboo stems [19], Rhizophora, giant reed, palm leaves, esparto grass [20], and many more. The synthesis of CNs requires that cellulose-concomitant components be removed from plant raw materials, and these processes inflict environmental damage [21].…”

Biocomposites of Cellulose Isolated from Coffee Processing By-Products and Incorporation in Poly(Butylene Adipate-Co-Terephthalate) (PBAT) Matrix: An Overview

“…Rizkiansyah et al [51] conducted a study in which they isolated cellulose from coffee pulp using an alkali treatment method with 3% weight of sodium hydroxide (NaOH), followed by a bleaching process with hydrogen peroxide. The research focused on determining the cellulose content in various stages of the pulp: firstly, in its washed state; secondly, after undergoing alkali treatment; and finally, post-alkali treatment and subsequent bleaching.…”