To evaluate the effects of surface modification with stearic acid on the dispersion of some inorganic fillers in polyethylene (PE) matrix, masterbatches containing 20–40 wt% of stearic acid uncoated and coated inorganic fillers and the linear low-density polyethylene (LLDPE) films containing 3–7% stearic acid uncoated and coated inorganic fillers were prepared. Two types of inorganic fillers used in the masterbatch included bentonite and silica. The structural change of inorganic fillers, whose surface was modified with stearic acid, was studied using IR spectroscopy. The dispersion of inorganic fillers in LLDPE matrix was evaluated using scanning electron microscope (masterbatch samples) and optical microscope (film samples). Changes in the melting temperature of LLDPE in the presence of inorganic fillers were evaluated by using differential scanning calorimeter (DSC). The mechanical properties of the films were evaluated according to ASTM D882. Surface-treated fillers with stearic acid dispersed in the masterbatches and films better than untreated fillers did. Stearic acid did not change the melting temperature of the filler/PE masterbatches. The mechanical properties of the films containing stearic acid coated fillers were higher than those containing unmodified fillers.

Recently, various environmental-friendly materials have been investigated and developed, especially composites of polylactic acid (PLA) and plant fibers. This paper investigates the effects of pulp fiber (PF) and epoxidized Tung oil (ETO) content on the properties of biocomposites, based on polylactic acid. The bleached pulp fiber reinforced PLA (PLA/PF) composites with 10–50 wt% fiber contents and 0–15% epoxidized Tung oil contents (with a certain number of fiber) were prepared in an internal mixer (Plastograph^® EC) at 150 °C. The mechanical properties of PLA/PF composites were improved significantly. The pulp fiber reinforced PLA composites, with the fiber content of 30 wt%, were found to have the highest mechanical properties. The tensile and flexural properties of PLA/Tung oil-soaked-pulp fiber composites were higher than those of PLA/Tung oil unsoaked pulp fiber composites. In addition, the degradation temperature of PLA-based composites decreased after adding more pulp fiber. The pulp fibers were well-dispersed in the PLA matrix with the content up to 30 wt%. The interaction between pulp fiber and PLA matrix improved by the addition of epoxidized Tung oil. Epoxidized Tung oil also improved tensile and flexural strength of composite materials when it was added with a number of below 10% of fiber.

This study focuses on the synthesis of superabsorbent polymers (SAPs) from jackfruit seed starch and acrylic monomers using the frontal polymerization (FP) method. Acrylic acid (AA) and acrylamide (AM) were grafted onto jackfruit seed starch with varying initiator contents (0.5, 0.75, 1, and 1.5 wt%) in the presence of MBA as a cross-linker (0.1 wt% relative to AA) to produce SAPs. The effect of external heat source temperature was also investigated. Using an external heat source at 1200 °C and a PPS initiator content of 1% resulted in SAPs JFSS-g-AA and JFSS-g-AM with water absorption capacities (WAC) of 415 g g⁻¹ and 298 g g⁻¹, respectively. In comparison, the conventional method yielded WACs of 364 g g⁻¹ and 273 g g⁻¹ for the same polymers. The synthesized polymers were characterized using FTIR, SEM, TGA, and XRD. The grafted polymers exhibited superior properties, including shorter reaction times and lower costs than conventional methods, as FP requires only an initial energy input to initiate polymerization, with no further energy needed. FP samples achieved reaction times of 19–21 min, significantly shorter than those of conventional samples (49 and 46 min, respectively). An increase in the external heat source temperature raised the front temperature, with a recorded peak of 126 °C. The frontal velocity was proportional to the initiator content, influencing the propagation of the reaction front. Compared to conventional polymerization, FP produced polymers with higher absorption capacity. These findings suggest that FP is a cost-effective and time-efficient alternative for synthesizing graft polymers from acrylic monomers and starch.