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Fabricating Reactive Surfaces with Brush-like and Crosslinked Films of Azlactone-Functionalized Block Co-Polymers
Published on: June 30, 2018
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High-performance and functional fully bio-based polylactic acid/polypropylene carbonate blends by in situ multistep
Lixin Song1, Weihan Chi1, Qian Zhang2
1Polymer High Functional Film Engineering Research Center of Liaoning Province, Shenyang University of Chemical Technology, Shenyang, Liaoning 110142, China; College of Materials Science and Engineering, Shenyang University of Chemical Technology, Shenyang 110142, China.
International Journal of Biological Macromolecules
|December 18, 2023
Summary
Grafting functional monomers onto polylactic acid (PLA) created a compatibilizer that significantly enhanced the mechanical properties and toughness of PLA/polypropylene carbonate (PPC) blends. This biodegradable material maintained optical and degradation performance, offering excellent comprehensive properties.
Area of Science:
- Polymer Science and Engineering
- Materials Science
- Sustainable Materials
Background:
- Polylactic acid (PLA) and polypropylene carbonate (PPC) are biodegradable polymers with distinct properties.
- Blending PLA and PPC can yield materials with improved characteristics, but compatibility issues often arise.
- Graft copolymers can act as compatibilizers to improve the miscibility and properties of polymer blends.
Purpose of the Study:
- To synthesize and characterize PLA-g-(GMA/MAH-co-St) graft copolymers using glycidyl methacrylate (GMA), maleic anhydride (MAH), and styrene (St).
- To investigate the effectiveness of these graft copolymers as compatibilizers in PLA/PPC blends.
- To evaluate the impact of varying GMA/MAH ratios on the blend's thermodynamics, rheology, optics, degradation, mechanical properties, and microstructure.
Main Methods:
- Solvent-free radical grafting technique to synthesize PLA-g-(GMA/MAH-co-St) copolymers.
- Melt blending of PLA, PPC, and the synthesized graft copolymers to form PLA/PPC/PLA-g-(GMA/MAH-co-St) blends.
- Comprehensive characterization of blend properties including thermodynamics, rheology, optics, degradation, mechanical testing, and microstructure analysis.
Main Results:
- Successful grafting of GMA, MAH, and St onto PLA, confirmed by increased grafting degree (up to 1.51 phr at GMA/MAH = 1.5/1.5 w/w).
- The optimal graft copolymer (GMA/MAH = 1.5/1.5 w/w) significantly improved blend compatibility, toughness (notch impact strength +184.6%, fracture elongation +535.4%), and thermal stability.
- The resulting blends maintained good melt flow properties (MFR 14.51 g/10 min), high transparency (91.56%), low haze (20.5%), and did not compromise degradation performance.
Conclusions:
- PLA-g-(GMA/MAH-co-St) graft copolymers effectively compatibilize PLA/PPC blends, leading to enhanced mechanical properties and toughness.
- The optimized graft copolymer composition (GMA/MAH = 1.5/1.5 w/w) yields a biodegradable blend with excellent comprehensive performance.
- This approach offers a promising route to develop high-performance, sustainable polymer materials.
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