Insight into the melt-processed polylimonene oxide/polylactic acid blends

• Published in: Polymer chemistry 2023-10, Vol.14 (39), p.453-4537
• Main Authors: Palenzuela, Miguel, Vega, Juan F, Souza-Egipsy, Virginia, Ramos, Javier, Rentero, Christian, Sessini, Valentina, Mosquera, Marta E. G
• Format: Article
• Language: English
• Subjects: Chemical synthesis; Degree of crystallinity; Glass transition temperature; Low molecular weights; Melt temperature; Miscibility; Polylactic acid; Polymer blends; Polymer chemistry; Room temperature; Thermal stability
• ISSN: 1759-9954; 1759-9962
• DOI: 10.1039/d3py00667k

In this work, the polymerization of limonene oxide (LO) has been optimized at room temperature with two different aluminium-based catalysts [AlMeX{2,6-(CHPh 2 ) 2 -4- t Bu-C 6 H 2 O}] (X = Me ( 1 ), Cl ( 2 )). A fully bio-based ether, polylimonene oxide (PLO), has been synthesized with low molecular weight and good thermal stability, being a potential sustainable polymeric additive for other bio-based and biodegradable polymers such as polylactic acid (PLA). Hence, we have explored its ability to influence the thermal, mechanical and morphological properties of PLA by preparing their blends by melt processing. The addition of a low amount of PLO led to a nearly 10 °C decrease in the PLA glass transition temperature. Moreover, a decrease in the PLA melting temperature and the degree of crystallinity was observed. Interestingly, a remarkable increase in the flexibility of PLA-based films was noticed. All the results point to the existence of strong interactions between the components, suggesting their partial miscibility. The addition of a small amount of PLO to PLA by melt processing leads to a decrease in the PLA's Tg, Tm and degree of crystallinity as well as a remarkable increase in PLA films flexibility. The strong interactions between PLO and PLA is unveiled.