Influence of PLA Flowability and Talc Content on the Performance of Rigid TPS/PBS/PLA/Talc Blends

Area of Science:

• Materials Science
• Polymer Science
• Sustainable Materials

Background:

• Compostable thermoplastic starch/poly(butylene succinate) (TPS/PBS) blends are explored for rigid applications.
• Optimizing their performance requires understanding the impact of additives like polylactic acid (PLA) and talc.

Purpose of the Study:

• To investigate how varying PLA flowability and talc content affects the mechanical and thermomechanical properties of TPS/PBS-based systems.
• To determine the optimal formulation for rigid packaging applications.

Main Methods:

• Synthesized twelve formulations of TPS/PBS with different PLA grades (varying melt flow index) and talc contents (0, 5, 10 wt%).
• Compounded materials using twin-screw extrusion and processed via injection moulding.
• Characterized materials using FTIR, DSC, and mechanical testing (modulus, tensile strength, elongation at break, HDT).

Main Results:

• PLA flowability significantly influenced phase distribution and interfacial adhesion.
• Talc addition increased structural heterogeneity and acted as a nucleating agent for the PBS phase, raising crystallization temperatures.
• Young's modulus increased with decreasing PLA flowability and increasing talc content (from 1.4 GPa to 2.7 GPa).
• Low-flow PLA formulations achieved higher tensile strength but lower elongation, while high-flow PLA offered a more balanced mechanical response.
• Hybrid PLA systems provided a balance of stiffness and elongation, and talc enhanced reinforcement but reduced deformability.

Conclusions:

• Combined control of PLA molecular characteristics and talc content allows for effective tuning of mechanical and thermomechanical performance.
• These optimized TPS/PBS/PLA/talc systems show potential for rigid packaging applications.
• Further research could explore other additives or processing techniques to further enhance properties.