Effect of Organic Modifier and Clay Content on Non-Isothermal Cold Crystallization and Melting Behavior of Polylactide/Organovermiculite Nanocomposites

Abstract

In clay/polymer nanocomposites, the crystallization behavior and kinetics of the polymer can be affected by the presence of clay, its content and the degree of miscibility between the clay and the polymer matrix. The effect of two different organomodified vermiculites on the non-isothermal cold crystallization and melting behavior of polylactide (PLA) was studied by differential scanning calorimetry (DSC). In the presence of vermiculites, the cold crystallization of PLA occurred earlier, particularly for the highest content of the most miscible organovermiculite with PLA. The cold crystallinity of PLA decreased at low heating rates, notably at high organoclay loadings, and increased at high heating rates, especially at low vermiculite contents. According to the crystallization half-time, crystallization rate coefficient (CRC), and crystallization rate parameter (CRP) approaches, the cold crystallization rate of PLA increased by incorporating vermiculites, with the effect being most noteworthy for the vermiculite showing better compatibility. The Mo model was successful in describing the non-isothermal cold crystallization kinetics of the PLA/vermiculite composites. The melting behavior was affected by the heating rate and the type and content of clay. The nucleating effect of the most compatible clay resulted in the less perfect crystallites. The activation energy was evaluated using the Kissinger and Takhor methods.

The Effect of Surface Treatment with Isocyanate and Aromatic Carbodiimide of Thermally Expanded Vermiculite Used as a Functional Filler for Polylactide-Based Composites

“…Even though this difference is small, it can indicate the nucleating effect of the filler on the matrix polymer. Fernandez and Fernandez described similar results in their work on polylactide/organovermiculite nanocomposites [65]. The influence of the filler on the crystallization of PLA is even more noticeable on the DSC thermogram recorded during cooling.…”

Evaluation of the Oil-Rich Waste Fillers’ Influence on the Tribological Properties of Polylactide-Based Composites

“…PLA-based filaments are also widely utilized in industrial or home fused deposition modeling (FDM) 3D printing [ 7 ]. As polylactide in its unfilled and unmodified form is characterized by low crystallinity and crystallization rate [ 8 ], low thermal stability [ 9 ], and brittleness [ 10 ], various fillers or modifying agents are commonly used to improve its properties and widen the application possibilities [ 11 ]. Additives of almost all types, from nanometric particles [ 12 ] to micrometric fibers [ 13 ], from functionalized compounds synthesized for special applications [ 14 ] to barely processed plant-based components [ 15 ] have been successfully applied in PLA, as it is reported in numerous scientific papers.…”

High-Performance Optical PET Analysis via Non-Isothermal Crystallization Kinetics

“…In the actual production process, polymer synthesis is mostly produced and processed by extrusion, injection molding and other methods under non-isothermal and dynamic conditions. Therefore, in order to obtain polymers with expected performance, Many researchers have devoted themselves to studying the non-isothermal crystallization kinetics of polymers, controlling the crystallization rate and crystallinity of polymers through effective synthesis methods to control their morphology and properties [ 5 , 6 , 7 , 8 , 9 ]. Differential scanning calorimetry (DSC) is usually used for non-isothermal crystallization analysis.…”