Investigations on Green Blends Comprising Biodegradable Polymer and Ionic Liquid.

Area of Science:

• Polymer Science
• Materials Science
• Green Chemistry

Background:

• Biodegradable polymers like poly(3-hydroxybutyrate) (PHB) offer sustainable alternatives.
• Ionic liquids are explored as potential plasticizers or modifiers for polymers.
• Understanding polymer-ionic liquid interactions is crucial for developing novel materials.

Purpose of the Study:

• To investigate the effect of an ionic liquid, 1-ethyl-3-propylimidazolium bis(trifluoromethanesulfonyl)imide {[EPrI][TFSI]}, on the crystallization behavior of PHB.
• To analyze the influence of {[EPrI][TFSI]} on the thermal properties and crystallization kinetics of PHB.
• To explore the interaction mechanisms between {[EPrI][TFSI]} and PHB.

Main Methods:

• Preparation of {[EPrI][TFSI]}/PHB blends.
• Differential Scanning Calorimetry (DSC) for thermal analysis (T_g, T_m, crystallinity).
• Avrami and Mo models for analyzing isothermal and non-isothermal crystallization kinetics.
• Fourier-transform infrared (FTIR) spectroscopy for interaction analysis.

Main Results:

• The addition of {[EPrI][TFSI]} decreased the glass transition temperature (T_g) and melting temperature (T_m) of PHB.
• {[EPrI][TFSI]} reduced the degree of crystallinity and slowed down both isothermal and non-isothermal crystallization rates of PHB.
• Avrami and Mo models confirmed the retarding effect of {[EPrI][TFSI]} on PHB crystallization, with increased F(T) indicating slower rates.
• FTIR analysis suggested ion-dipole interactions and potential complexation between {[EPrI][TFSI]} and PHB.

Conclusions:

• {[EPrI][TFSI]} acts as a crystallization inhibitor for PHB, weakening its crystalline structure.
• The interaction between the ionic liquid and the polymer is likely ion-dipole in nature, possibly forming complexes.
• These findings provide insights into modifying the properties of biodegradable polymers using ionic liquids for tailored applications.