The properties of poly(lactic acid)/starch blends with a functionalized plant oil: Tung oil anhydride

• Published in: Carbohydrate polymers 2013-06, Vol.95 (1), p.77-84
• Main Authors: Xiong, Zhu, Li, Chao, Ma, Songqi, Feng, Jianxian, Yang, Yong, Zhang, Ruoyu, Zhu, Jin
• Format: Article
• Language: English
• Subjects: Anhydrides - chemistry; Applied sciences; Calorimetry, Differential Scanning; Exact sciences and technology; Fourier transform infrared spectroscopy; Lactic Acid - chemistry; maleic anhydrides; mechanical properties; Microscopy, Electron, Scanning; Natural polymers; Physicochemistry of polymers; Plant Oils - chemistry; Plasticizer; plasticizers; Plasticizers - chemistry; Poly(lactic acid); Polyesters; polylactic acid; Polymers - chemistry; scanning electron microscopy; Spectroscopy, Fourier Transform Infrared; Starch; Starch - chemistry; Starch and polysaccharides; thermal properties; tung oil; Tung oil anhydride
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2013.02.054

The diagram of TOA layer formed on the starch particle via the possible reaction between hydroxyl groups of starch and maleic anhydride groups of TOA during the melt-blending process. [Display omitted] ► Tung oil anhydride could be used as a bio-based reactive plasticizer for PLA/starch compounds. ► TOA could enrich on starch and increase the compatibility of PLA/starch blends via reaction. ► It has no report about tung oil anhydride influencing the properties of PLA/starch blends. Bio-sourced polymers, polylactide (PLA) and starch, have been melt-blended by lab-scale co-extruder with tung oil anhydride (TOA) as the plasticizer. The ready reaction between the maleic anhydride on TOA and the hydroxyl on starch led TOA molecules to accumulate on starch and increased the compatibility of PLA/starch blends, which was confirmed by FT-IR analyses and SEM. The TOA could change the mechanical properties and physical behaviors of PLA/starch blends. DSC and DMA analysis show that the TOA layer on starch has an effect on the thermal behavior of PLA in the ternary blend. The enrichment of TOA on starch improves the toughness and impact strength of the PLA/starch blends. The adding amount of TOA in PLA/starch blends primarily determined the compatibility and mechanical properties of the resulted ternary blends. The tensile and impact fracture modes of the PLA/starch blend with or without TOA has also been investigated by SEM analysis.