Polylactic Acid and Polybutylene Succinate Biopolymer Blends for Extrusion Processing: Dry Blending vs. Masterbatch...

Area of Science:

• Polymer Science
• Materials Science
• Sustainable Materials

Background:

• Growing environmental concerns drive demand for biobased and biodegradable polymers like polylactic acid (PLA) and polybutylene succinate (PBS).
• Blending PLA and PBS enhances material performance, mitigating PLA's inherent brittleness.
• Processing methods, including single-screw extrusion (SSE) and twin-screw extrusion compounding followed by SSE (TSSE), influence blend properties.

Purpose of the Study:

• To comprehensively investigate and compare the SSE and TSSE processing routes for PLA/PBS blends.
• To assess the impact of these processing methods on the physical, morphological, and mechanical characteristics of PLA/PBS blends.
• To determine the feasibility of a simplified, single-step SSE process for PLA/PBS blending.

Main Methods:

• Comparative analysis of PLA/PBS blends processed via SSE and TSSE.
• Evaluation of physical, morphological, and mechanical properties, including molecular weight, domain morphology, elongation at break, and yield strength.
• Assessment of degradation behavior and miscibility.

Main Results:

• Both SSE and TSSE produced PLA/PBS blends with comparable overall performance.
• PLA molecular weight degradation was significantly higher in TSSE (~18.7%) than in SSE (~1.5%).
• Morphological differences were observed, with TSSE yielding slightly finer PBS domains, but these did not impact mechanical properties or miscibility significantly. Elongation at break improved dramatically in both methods with PBS addition.

Conclusions:

• The single-step SSE process is a viable, cost-effective, and energy-efficient alternative to TSSE for producing PLA/PBS blends.
• The SSE method avoids the need for pre-compounding, simplifying the manufacturing process.
• PLA/PBS blends processed via SSE demonstrate robust performance, comparable to those from more complex methods.