Norwahyuni Mohd Yusof

The growing demand for sustainable packaging materials has accelerated interest in biomass-derived carbon fillers as functional reinforcements for biodegradable polymer composites. This review critically evaluates the use of carbon materials produced from agricultural residues, particularly palm kernel shell (PKS) and coconut shell (CS), in biopolymer composite coating films for food packaging applications. Recent thermochemical conversion routes, including carbonization, activation, and catalytic graphitization, are discussed in relation to their influence on filler morphology, porosity, surface chemistry, and graphitic ordering. Particular emphasis is placed on structure–property relationships in composite systems containing matrices such as polylactic acid (PLA), starch, chitosan, gelatin, and polyvinyl alcohol (PVA). Published studies indicate that properly dispersed carbon fillers can improve tensile strength, thermal stability, ultraviolet shielding, and oxygen/water vapor barrier performance through stress-transfer mechanisms and tortuous diffusion pathways. However, excessive filler loading or poor interfacial compatibility frequently causes agglomeration, brittleness, and loss of transparency. Surface modification strategies including oxidation, silanization, and surfactant-assisted dispersion, are therefore reviewed as key approaches to optimize composite performance. Finally, current limitations involving migration safety, process scalability, and the lack of standardized testing protocols are discussed. Overall, PKS- and CS-derived carbon fillers represent promising sustainable additives for next-generation biopolymer composite packaging systems.

Carboxymethyl cellulose (CMC) and polyvinyl alcohol (PVOH) composite films incorporated with glycerol and citric acid were examined for development of biodegradable films with improved water resistance properties. Addition of citric acid at 30% effectively reduced water solubility of the film. To prepare functional active packaging films for storage of perishable products, the role of activated carbon (AC) at different percentages was also investigated. Various physical, mechanical, thermal, and functional properties of these films were then characterized. The study found that the inclusion of AC at 0.25, 0.5, and 0.75% did not affect the tensile strength (TS), elongation at break, and thermal properties, resulting in stronger films. Fourier transform infrared analysis suggested intermolecular interactions within the polymer matrix after incorporation of citric acid and activated carbon. The antimicrobial activity test revealed no inhibition zone; however, there was no noticeable increase or spread of bacteria during the testing period.

As sustainability and food safety continue to gain more attention, the demand for environmentally friendly packaging materials has increased significantly. This review emphasizes the transformative potential of activated carbon derived from renewable sources in addressing critical challenges in food packaging. Activated carbon is recognized for its outstanding adsorption capacity, large surface area, and porous structure, which enable it to capture gases such as oxygen, moisture, and ethylene, all of which contribute to food deterioration. In addition to these properties, activated carbon exhibits antimicrobial activity and can facilitate the release of nanoparticles, thereby enhancing food safety through the inhibition of microbial growth. Its multifunctional characteristics make it suitable for various uses, including prolonging shelf life and maintaining the sensory attributes of food products. The local production of activated carbon from agricultural residues supports circular economy practices by reducing reliance on fossil-based resources and minimizing environmental impact. This review highlights the important role of activated carbon in the development of sustainable and multifunctional food packaging technologies that support global initiatives aimed at reducing plastic waste and promoting green innovation.

Engineered laminated bamboo plays a crucial role in structural applications, addressing challenges such as bamboo’s natural variability, species differences, adhesives, and loading direction. This study examines the bending performance of three-layered laminated bamboo configurations using two species, Gigantochloa scortechinii and G. levis, bonded with phenol-resorcinol-formaldehyde (PRF) and polyurethane (PUR) adhesives. Laminated bamboo was assembled with lay-up patterns (parallel and perpendicular) and arrangements (vertical, horizontal, and mixed). Four-point bending tests under flatwise and edgewise loading were used to determine flexural performance and failure modes. Results showed that PUR-bonded bamboo had lower thickness swelling (TS) and water absorption (WA). While bamboo species did not significantly affect bending performance, the adhesive type, lay-up pattern, and arrangement were influential. Flatwise loading improved the modulus of elasticity (MOE) by 5% but reduced the modulus of rupture (MOR) by 10% compared to edgewise loading. PRF-bonded bamboo outperformed PUR in strength, making it preferable for structural use. Vertical arrangements with PRF and PUR adhesives yielded optimal bending performance, emphasizing the importance of adhesive selection and configuration in enhancing laminated bamboo’s structural properties.