Production of high-purity cellulose, cellulose acetate and cellulose-silica composite from babassu coconut shells

Electrospun Nanocomposites Containing Cellulose and Its Derivatives Modified with Specialized Biomolecules for an Enhanced Wound Healing

“…An extra hydroxylation step is required for producing CA with the desired DS [21]. CA production entails very high-quality cellulose as raw material, with a high alpha cellulose content [21,[105][106][107][108][109][110]. This high-quality cellulose is generally obtained from cotton or wood dissolving pulp, where the cellulose rate is generally more than 95%.…”

“…Alternative sources of cellulose have been researched, finding lignocellulosic biomass as an attractive alternative due to its renewability and large availability worldwide. Preliminary work has uncovered some important sources of CA that are based on biomass that include microcrystalline cellulose (MCC), cotton linter pulp, wheat straw pulp, bamboo pulp, bleached softwood sulfite dissolving pulp, bleached hardwood kraft pulp (HP) [21], oil palm empty fruit bunches [105], sugarcane straw [106], waste cotton fabrics [107], sugarcane bagasse [108], sorghum straw [109], babassu coconut shells [110] and waste polyester/cotton blended fabrics (WBFs) [111]. Still, there is a long way until process optimization occurs, since there are major barriers to the production of cellulose-containing products from agricultural residues, including the heterogeneity of the raw material, the processing conditions reproducibility, the heterogeneous phase of the synthesis reaction, the difficulty of purification, the effluent disposal, and the control of product quality [112].…”

“…Many researchers apply alkali or acid pretreatment to remove lignin and hemicellulose of material resources to increase the yield of CA production from wastes, affecting the cellulose crystalline structure, which then becomes more amorphous [110,112,113]. For instance, L. Cao et al used diluted phosphoric acid at different temperatures and B. Ass et al used NaOH to disrupt the crystalline structure of cellulose, which increases the amorphous region and renders cellulose more accessible to acetic anhydride, resulting in an acetylation process more effective for CA production [113,114].…”

“…Additionally, H.R. Amaral et al resorted to acid pretreatment of babassu coconut shells to increase the yield of the acetylation of cellulose to obtain CA [110]. These works have shown the importance of pretreating lignocellulosic biomass to increase CA synthesis yield.…”

“…These works have shown the importance of pretreating lignocellulosic biomass to increase CA synthesis yield. However, bio-residues from these treatments are a serious environmental challenge due to their aggregation with household wastes, causing disturbances in the ecological cycle of the soil, and resulting in soil infertility and environmental pollution; thus, attention should be urgently paid [110,113,115]. A great opportunity has arisen to explore more of these bio-based polymers and their alternative production methods, given the current environmental and energy policies.…”