Insoluble starch composite foams produced through microwave expansion

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Materials Engineering

Background:

• Biocomposites offer sustainable alternatives in various applications.
• Starch and chitosan are abundant biopolymers with tunable properties.
• Understanding swelling behavior is crucial for biocomposite design.

Purpose of the Study:

• To prepare an insoluble biocomposite from potato starch and chitosan via microwave treatment.
• To investigate the influence of pH and chitosan content on the swelling behavior of the biocomposite.
• To analyze the structural integrity and microstructure of the developed biocomposite.

Main Methods:

• Microwave-assisted synthesis of potato starch-chitosan biocomposite.
• Swelling studies conducted at varying pH values (2, 6.8, 12).
• Analysis of liquid absorption using solution uptake ratio.
• Chitosan content variation to assess its impact on swelling.
• Glucose analysis via ion exchange chromatography to evaluate hydrolysis.
• Microstructural investigation using Field Emission Scanning Electron Microscopy (FE-SEM).

Main Results:

• The biocomposite's swelling ratio is significantly influenced by pH and chitosan content.
• Higher swelling was observed at pH values below the pKa of chitosan's amine groups (~6.3).
• Composites with increased chitosan content demonstrated enhanced liquid absorption.
• Minimal hydrolysis of the biocomposite was detected at low pH conditions.
• FE-SEM revealed the microstructure of the prepared biocomposite.

Conclusions:

• The potato starch-chitosan biocomposite exhibits pH-dependent swelling, favoring acidic environments.
• Chitosan content is a critical factor in controlling the swelling capacity of these biocomposites.
• The developed biocomposite demonstrates good stability against hydrolysis in acidic media.
• Microwave treatment is an effective method for preparing functional starch-chitosan biocomposites.