Carboxymethyl cellulose (CMC) is obtained from Vietnamese pineapple leaf waste through etherification. By treating pineapple leaf powder with a solution of NaOH then with HNO₃ at 90°C for an appropriate time, cellulose can be efficiently extracted. To obtain CMC, carboxymethylation was performed by reaction of the pineapple cellulose with chloroacetic acid at 60°C for 1.5h. The optimal conditions for this reaction were established. The resulting CMC had a degree of substitution (DS) of 0.91. The hydrogel was prepared by graft copolymerization of acrylic acid and acrylamide to the synthesized CMC. During that reaction, N,Nmethylenebisacrylamide (MBA) served as the crosslinking agent and ammonium persulfate (APS) as the initiator. The maximum hydrogel absorbencies for distilled water and 0.9wt. NaCl solution were relatively high, namely, 588.2g/g and 79.3g/g, respectively. Additionally, the water swelling and water retention behaviors of the hydrogel in soil were also investigated. The results showed that this hydrogel can be employed as a suitable moisture-holding additive in soil for cultivation purposes.

Thermoplastic chitosan/microcrystalline cellulose (TPC/MCC) composite films were prepared by thermo-compression and are reported here for the first time. L-lactic acid (LLA) was used as a plasticizer in the formation of TPC. TPC films with varying LLA contents and the TPC/MCC composite films with different MCC contents were produced for evaluation. The physicochemical, mechanical, and antibacterial properties of the thermo-compressed TPC and TPC/MCC films were characterized. LLA enhanced thermal stability and crystallinity, improved film flexibility, and reduced the water solubility of the chitosan matrix. Incorporation of MCC further improved mechanical properties and decreased water dissolution. Tensile testing showed that the addition of 5 wt% MCC increased maximum tensile strength by 82% and Young’s modulus by 124%. All TPC and TPC/MCC films exhibited antibacterial activities against both Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. Antibacterial efficacy decreased as MCC content increased to 20 wt%. These thermo-compressed TPC/MCC films can be tailored to display a range of properties by adjusting the contents of LLA and MCC, making them well suited for antibacterial food-packaging applications.

Poly(L-lactide)-b-poly(ethylene glycol)-b-poly(L-lactide) (PLLA-PEG-PLLA) shows promise for use in bioplastic applications due to its greater flexibility over PLLA. However, further research is needed to improve PLLA-PEG-PLLA’s properties with appropriate fillers. This study employed zinc phenylphosphate (PPZn) as a multi-functional filler for PLLA-PEG-PLLA. The effects of PPZn addition on PLLA-PEG-PLLA characteristics, such as crystallization and thermal and mechanical properties, were investigated. There was good phase compatibility between the PPZn and PLLA-PEG-PLLA. The addition of PPZn improved PLLA-PEG-PLLA’s crystallization properties, as evidenced by the disappearance of the cold crystallization temperature, an increase in the crystallinity, an increase in the crystallization temperature, and a decrease in the crystallization half-time. The PLLA-PEG-PLLA’s thermal stability and heat resistance were enhanced by the addition of PPZn. The PPZn addition also enhanced the mechanical properties of the PLLA-PEG-PLLA, as demonstrated by the rise in ultimate tensile stress and Young’s modulus. We can conclude that the PPZn has potential for use as a multi-functional filler for the PLLA-PEG-PLLA composite due to its nucleating-enhancing, thermal-stabilizing, and reinforcing ability.