Structural and physicochemical properties of melt-quenched poly(ethylene carbonate)/poly(lactic acid) blends. (May 2019)

• Record Type: Journal Article
• Authors: Ramlee, N.A.; Tominaga, Y.
• Is Part Of: Polymer degradation and stability. Volume 163(2019)
• Page Start: 35
• Page End: 42
• Publication Date: 2019-05
• Subjects: Poly(ethylene carbonate) -- Poly(lactic acid) -- Polymer blend -- Biodegradable -- Melt-quench; Polymers -- Deterioration -- Periodicals; Stabilizing agents -- Periodicals; Polymères -- Dégradation -- Périodiques; Stabilisants -- Périodiques; 668.9
• DOI: 10.1016/j.polymdegradstab.2019.02.028
• Languages: English
• ISSNs: 0141-3910

Abstract

Abstract: The effect of the melt-quench process on the thermal, structural and mechanical properties of partially miscible poly(ethylene carbonate) (PEC)/poly (lactic acid) (PLA) blends was investigated. The differential scanning calorimetry (DSC) and X-ray diffraction (XRD) measurements found a largely amorphous phase of melt-quenched PEC/PLA blends, with crystallinity in the range 6–12%, depending on the PEC and PLA ratios. The high chain mobility of PEC reduces the cold-crystallization temperature of PLA for the melt-quenched PEC/PLA blends by more 12 °C, as in the PEC60/PLA40 blend. Upon the rapid cooling, however, the morphology of PEC/PLA blend changes to enhance the toughness, especially for the PLA-rich blend. Addition of 10 wt% PEC to PLA slightly improved the tensile toughness, from 5.1 MJ/m 3 to 5.5 MJ/m 3, in which ductile PEC improves the toughness of PLA. SEM images of the quenched fracture cross-section of melt-quenched PEC/PLA blends confirmed that PEC and PLA are compatible, with a two-phase structure in which small PLA domains are distributed in the continuous PEC phase. This structure is responsible for the high interfacial adhesion in the sea-island morphology of PEC-rich blends, giving improved resistance to failure of PEC. Highlights: Melt quenching reduces PEC/PLA blends crystallinity. The PLA blends with 60 wt% of PEC decreases PLA crystallization temperature. Small PLA domains distributed in the continuous PEC phase. Melt-quenched PEC/PLA blend represents established thermal degradability.