Experimental Studies and Modeling of the Drying Kinetics of Multicomponent Polymer Films

Area of Science:

• Materials Science
• Chemical Engineering
• Polymer Science

Background:

• Drying thin polymer films is crucial for product structure, solid state, and stability.
• Understanding drying kinetics is essential for optimizing film manufacturing processes.
• Multicomponent polymer films require specific drying strategies due to varied polymer properties.

Purpose of the Study:

• To investigate and model the drying kinetics of multicomponent films composed of hydroxypropyl methylcellulose (HPMC) and polyvinyl alcohol (PVA).
• To explore the influence of temperature on the drying process of these polymer films.
• To correlate solid-state changes with drying mechanisms.

Main Methods:

• Isothermal drying kinetics were studied using thermo-gravimetric analysis (TGA) and convection oven methods at 40, 60, and 80°C.
• Solid-state characterization employed polarization microscopy, hot-stage microscopy, scanning electron microscopy (SEM), and differential scanning calorimetry (DSC).
• The three-parameter Hill equation was utilized to model the experimental drying data.

Main Results:

• Drying kinetics of HPMC and PVA films were comparable between TGA and convection oven methods.
• The Hill equation successfully modeled the experimental drying kinetics, with the time factor τ indicating two distinct drying phases.
• Solid-state phase changes during dehydration significantly impacted drying kinetics and mechanisms.

Conclusions:

• The three-parameter Hill equation provides a robust model for drying kinetics and solvent diffusion mechanisms in polymer films.
• TGA serves as an effective tool for determining drying endpoints in industrial processes.
• This research enhances the understanding of thin film drying, particularly for pharmaceutical applications.