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Study of Morphology, Rheology, and Dynamic Properties toward Unveiling the Partial Miscibility in Poly(lactic
Hu Qiao1, Abderrahim Maazouz1, Khalid Lamnawar1
1Univ Lyon, CNRS, UMR 5223, Ingénierie des Matériaux Polymères, INSA Lyon, Université Claude Bernard Lyon 1, Université Jean-Monnet, F-69621 Villeurbanne, France.
Polymers
|December 23, 2022
Summary
This study explores poly(lactic acid) (PLA) and poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) blends, revealing how composition impacts their properties. Degradation influences miscibility and rheology, offering insights for material design.
Area of Science:
- Polymer Science and Engineering
- Materials Science
- Rheology
Background:
- Poly(lactic acid) (PLA) and poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) are biodegradable polymers with distinct properties.
- Understanding their blend behavior is crucial for developing advanced bioplastics.
- Melt mixing is a common technique for polymer blend preparation.
Purpose of the Study:
- To fundamentally understand how composition and physico-chemical properties affect the rheology, morphology, miscibility, and thermal stability of PLA/PHBV blends.
- To investigate the influence of melt processing on blend characteristics.
- To correlate thermo-rheological complexity with blend morphology and miscibility.
Main Methods:
- Melt mixing of PLA and PHBV.
- Rheological analysis: dynamic time sweep (DTS), small-amplitude oscillatory shear (SAOS).
- Thermal analysis: Differential Scanning Calorimetry (DSC), Dynamic Mechanical Analysis (DMA).
- Morphological analysis: Scanning Electron Microscopy (SEM).
- Spectroscopic analysis: Dielectric Relaxation Spectroscopy (DRS).
- Chromatographic analysis: Size-Exclusion Chromatography (SEC).
Main Results:
- PHBV exhibits inherent thermal degradation, necessitating restricted processing conditions.
- PLA/PHBV blends show thermo-rheological complexity, particularly PLA-rich compositions, due to mismatched viscoelastic properties and phase separation.
- Melt-induced degradation contributes to self-compatibilization and plasticization, improving miscibility and simplifying rheology in PHBV-rich blends at lower temperatures.
Conclusions:
- The study elucidates the complex interplay between composition, processing, degradation, and properties in PLA/PHBV blends.
- Degradation plays a significant role in modifying blend miscibility and rheological behavior.
- Findings provide a basis for controlling the micro/nanostructure and optimizing the performance of PLA/PHBV biopolymer blends.
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