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A Facile and Eco-friendly Route to Fabricate PolyLactic Acid Scaffolds with Graded Pore Size
Published on: October 17, 2016
Fabricating High-Thermal-Conductivity, High-Strength, and High-Toughness Polylactic Acid-Based Blend Composites via
De-Xiang Sun1, Ting Gu1, Yu-Tong Mao1
1Key Laboratory of Advanced Technologies of Materials (Ministry of Education), School of Materials Science & Engineering, Southwest Jiaotong University, Chengdu 610031, China.
This study developed biodegradable poly(l-lactic acid)/poly(butylene adipate-co-butylene terephthalate)/carbon nanofiber composites using melt extrusion-stretching. The process created oriented microstructures, significantly enhancing thermal conductivity and mechanical properties for sustainable material applications.
Area of Science:
- Materials Science
- Polymer Science
- Nanotechnology
Background:
- Plastic waste is a significant environmental concern, driving the need for biodegradable alternatives.
- Poly(l-lactic acid) (PLLA) based composites offer a sustainable solution but face challenges in achieving high thermal conductivity and mechanical strength.
- Tailoring microstructure is crucial for optimizing the performance of PLLA composites.
Purpose of the Study:
- To fabricate biodegradable PLLA/PBAT/CNF blend composites with enhanced thermal and mechanical properties.
- To investigate the effect of melt extrusion-stretching on the microstructure and properties of PLLA/PBAT/CNF composites.
- To explore the potential of oriented microstructures and annealing treatments for further property enhancement.
Main Methods:
- Fabrication of PLLA/PBAT/CNF blend composites using a melt extrusion-stretching method.
- Characterization of microstructures, including molecular chain orientation, dispersed phase morphology, and carbon nanofiber alignment.
- Evaluation of thermal conductivity, tensile strength, and elongation at break.
- Analysis of the effects of annealing on oriented crystal structures and material properties.
Main Results:
- Melt extrusion-stretching induced multioriented microstructures (oriented PLLA chains, elongated PBAT, aligned CNFs).
- The oriented microstructure significantly improved in-plane thermal conductivity (1.53 Wm⁻¹K⁻¹), tensile strength (66.8 MPa), and elongation at break (56.5%) at 10 wt% CNF.
- Annealing of extrusion-stretched samples further enhanced thermal conductivity, heat resistance, and mechanical properties through the formation of oriented crystal structures.
Conclusions:
- The melt extrusion-stretching method effectively creates oriented microstructures in PLLA/PBAT/CNF composites, leading to superior thermal and mechanical performance.
- The multioriented structure promotes CNF network formation, enhancing thermal conductivity, while chain and fiber orientation improve mechanical strength and toughness.
- This study provides a novel approach for developing high-performance, biodegradable PLLA-based composites with excellent thermal conductivity, mechanical properties, and heat resistance.
