Optimization of starch foam extrusion through PVA polymerization, moisture content control, and CMCS incorporation for enhanced antibacterial cushioning packaging

• Published in: Carbohydrate polymers 2025-01, Vol.347, p.122763, Article 122763
• Main Authors: Liu, Fengsong, Cao, Yifang, Ren, Jiahao, Xie, Yijia, Xiao, Xinglong, Zou, Yucong, Bai, Hong, Zhang, Xiaowei, Chen, Ying
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - pharmacology; Antibacterial activity; antibacterial properties; chitosan; Chitosan - analogs & derivatives; Chitosan - chemistry; Escherichia coli - drug effects; Extrusion; foams; Hydrophobic and Hydrophilic Interactions; hydrophobicity; Melt strength; Polymerization; polyvinyl alcohol; Polyvinyl Alcohol - chemistry; PVA polymerization; Staphylococcus aureus - drug effects; starch; Starch - analogs & derivatives; Starch - chemistry; Starch-based foam; strength (mechanics); Water - chemistry; water content; water uptake
• ISSN: 0144-8617; 1879-1344; 1879-1344
• DOI: 10.1016/j.carbpol.2024.122763

Melt strength and moisture content are critical parameters in starch foam extrusion, as they dictate bubble expansion dynamics, which subsequently determine the foam's properties. Despite continuous advancements in the development and application of starch foams, challenges such as water resistance, mechanical strength, and antibacterial activity remain unresolved. This research investigates the influence of polyvinyl alcohol (PVA) polymerization and moisture content on the properties of extruded foam while also exploring the potential for enhancing antimicrobial functionality by incorporating carboxymethyl chitosan (CMCS) into conventional starch foams. The findings underscore the significance of melt strength and intermolecular entanglements in shaping foam characteristics, confirming that bioactive components effectively improve hydrophobicity, foaming characteristics, and antibacterial capabilities. Moreover, by precisely regulating PVA polymerization and moisture content, it became feasible to optimize foam properties and achieve the desired performance. Specifically, foam with a moisture content of 12 % and a PVA polymerization degree of 1700 exhibited exceptional performance, including the highest foaming ratio of 45.62, the minimal water absorption rate of 6.31 %, and the greatest recovery rate of 88.95 %. Furthermore, increasing CMCS concentrations substantially enhances the antibacterial properties of the foam, demonstrating its potential for application in antibacterial cushioning packaging and emphasizing its versatility and practicality. Schematic diagram of starch foam fabrication. Synopsis: Through precise control of moisture content and PVA polymerization degree, it became feasible to effectively manipulate the intricate relationship among melt viscoelasticity, cell structure, and foaming behavior during the extrusion process, thus achieving the synergistic improvement of hydrophobicity, mechanical properties, and antimicrobial functionality on the starch-based foams. [Display omitted] •The 1700 degree of PVA polymerization indicated higher melt strength.•The starch-based materials had better foam properties at 12 % moisture content.•the incorporation of CMCS enhanced the antimicrobial activity of the foam.•Foams showed improved hydrophobic, mechanical and antibacterial properties.