Choline chloride vs choline ionic liquids for starch thermoplasticization.

Area of Science:

• Polymer Science
• Materials Science
• Biomaterials

Background:

• Native starch requires plasticizers for melt processing into thermoplastic materials.
• Glycerol is a common starch plasticizer, but its efficiency can be limited.
• Choline salts, including ionic liquids, are explored as alternative plasticizers.

Purpose of the Study:

• To compare the effectiveness of glycerol and various choline salts as plasticizers for native starch during melt processing.
• To investigate the impact of different choline salts on starch macromolecular structure and processing energy.
• To evaluate the final properties of thermoplastic starch plasticized with choline salts.

Main Methods:

• Melt processing of native starch (12% water) with 23% plasticizers at 120°C using compression molding and microextrusion.
• Comparison of glycerol with choline chloride, choline acetate, and choline lactate.
• Analysis of starch macromolecular structure changes and thermomechanical properties.

Main Results:

• Ionic plasticizers (choline acetate, choline lactate) enabled more efficient starch melting than glycerol.
• Starch chain scission was observed with ionic plasticizers, reducing energy requirements for thermoplasticization.
• Raw choline chloride provided a balance between limited chain scission and favorable water uptake and thermomechanical properties.

Conclusions:

• Choline salts, particularly ionic liquids, enhance native starch melt processing efficiency.
• Raw choline chloride presents a favorable compromise for starch thermoplasticization, balancing processing and final material characteristics.