Vitrimeric Polylactide by Two-step Alcoholysis and Transesterification during Reactive Processing for Enhanced Melt
Yong-Bo Liu1, Li-Mei Peng1, Rui-Ying Bao1
1State Key Laboratory of Polymer Materials Engineering, College of Polymer Science and Engineering, Sichuan University, Chengdu 610065, Sichuan, China.
ACS Applied Materials & Interfaces
|September 27, 2022
Summary
This study enhances polylactide (PLA) melt strength using PLA vitrimers, enabling advanced biobased foams. These improved PLA vitrimers offer a sustainable alternative to fossil-based foams.
Area of Science:
- Polymer Chemistry
- Materials Science
- Sustainable Materials
Background:
- Polylactide (PLA) exhibits low melt strength, limiting its use in advanced biobased and biodegradable foams.
- Fossil-based polymer foams dominate the market, highlighting the need for sustainable alternatives.
Purpose of the Study:
- To enhance the melt strength of polylactide (PLA) for improved foam applications.
- To develop PLA vitrimers as a viable, sustainable alternative to fossil-based foams.
Main Methods:
- Two-step reactive processing of commercial PLA thermoplastics, glycerol, and diphenylmethane diisocyanate (MDI).
- Utilized Zn(II)-catalyzed addition and transesterification chemistry, including alcoholysis for chain modification.
- Employed supercritical carbon dioxide foaming technique to assess foamability.
Main Results:
- Developed PLA vitrimers with significantly improved melt strength and strain hardening.
- Achieved thermoplastic processability via extrusion and compression.
- Obtained microcellular PLA foams with a 49.2-fold expansion ratio and uniform cell morphology.
Conclusions:
- PLA vitrimers offer a scalable method to enhance PLA melt strength, broadening its applicability.
- This advancement supports the realization of a sustainable society by providing eco-friendly foam solutions.
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