Thermal and Rheological Properties of Fischer–Tropsch Wax/High‐Flow LLDPE Blends

Abstract

Waxes find use as processing aids in filled compounds and polyethylene‐based masterbatches. In such applications, the thermal and physical property changes they impart to the polymer matrix are important. Therefore, this study details results obtained for blends prepared by mixing a Fischer–Tropsch (F–T) wax with a high‐flow linear low‐density polyethylene (LLDPE). The melting and crystallization behavior are studied using hot‐stage polarized optical microscopy (POM) and differential scanning calorimetry (DSC). The calorimetry results are consistent with partial cocrystallization of the two components. The melting and crystallization exo‐ and endotherms for the wax‐ and LLDPE‐rich phases remained separate. However, they change in shape and shift toward higher‐ and lower temperature ranges, respectively. It is found that increasing the wax content delays the crystallization, decreases the overall crystallinity, and reduces the size of the crystallites of the polyethylene‐rich phase. Rotational viscosity is measured at 170 °C in the Newtonian shear‐rate range. The variation of the zero‐shear viscosity with blend composition is consistent with the assumption of a homogeneous melt in which the chains are in an entangled state. Therefore, it is concluded that the wax and LLDPE are, in effect, miscible in the melt and partially compatible in the solid state.

Structural characterization of Lactobacillus plantarum M616 microcapsule powder and its in vitro digestion and colonization in gut

“…The establishment of in vitro digestion models refers to the methods of Versantvoort et al ( 2005) and [19] Pinto et al (2014). Accurately weigh 10 g of microcapsule powder in a triangular bottle, add 50 g of the con gured simulated gastric juice, shake evenly, and place it on a shaker at 37°C and shake for 2 h.…”

“…Analyzing the melting behavior of polymer blends is an effective way to evaluate the miscible phase of blends (Mhlabeni et al 2023). In DSC analysis, when a substance undergoes a phase transition, the sample absorbing energy exhibits characteristic endothermic peaks Sorbitol and EHSPI had melting endothermic peaks around 99 °C and 70 °C, respectively, 2-HP-β-CD did not have obvious endothermic peaks and exothermic peaks in the test range, and Lactobacillus plantarum microcapsules only had endothermic peaks at about 50 °C, and did not have the original exothermic peaks of D-sorbitol and EHSPI.…”