Sorption of ionic liquids in soil enriched with polystyrene microplastic reveals independent behavior of cations and anions

Recently, much attention has been focused on the application of the Ionic Liquids (ILs) with herbicidal activity in agriculture. It has been suggested that through the appropriate selection of cations and anions, one can adjust the properties of ILs, particularly the hydrophobicity, solubility, bioavailability, toxicity. In practical agricultural conditions, it will be beneficial to reduce the mobility of herbicidal anions, such as the commonly applied 2,4-dichlorophenoxyacetic acid [2,4-D] in the soil. Furthermore, microplastics are becoming increasingly prevalent in the soil, potentially stimulating herbicidal sorption. Therefore, we investigated whether cations in ILs influence the mobility of anions in OECD soil supplemented with polystyrene microplastic (PS). For this purpose, we used the 2,4-D based ILs consisting of: a hydrophilic choline cation [Chol][2,4-D] and a hydrophobic choline cation with a C12chain [C12Chol][2,4-D]. Characterization of selected micropolystyrene was carried out using the BET sorption-desorption isotherm, particle size distribution and changes in soil sorption parameters such as soil sorption capacity and cation exchange capacity. Based on the batch sorption experiment, the effect of microplastic on the sorption of individual cations and anions in soil contaminated with micropolystyrene was evaluated. The results obtained indicate that the introduction of a 1-10% (w/w) PS resulted in an 18-23% increase of the soil sorption capacity. However, the sorption of both ILs' cations increased only by 3-5%. No sorption of the [2,4-D] anion was noted. This suggests that cations and anions forming ILs, behave independently of each other in the environment. The results indicate the fact that ILs upon introduction into the environment are not a new type of emerging contaminant, but rather a typical mixture of ions. It is worth noting that when analyzing the behavior of ILs in the environment, it is necessary to follow the fate of both cations and anions.

The new functional filler TiO2-SiO2/polyhedral oligomeric hybrid silsesquioxane as a potential modifier of polyethylene

The paper presents preliminary application studies of the innovative TiO2-SiO2/ POSS filler as a potential low-density polyethylene modifier. It was found that the addition of the filler increases the stiffness and hardness of the composite and slightly changes the intensity of its color.

The Influence of Sub-Zero Conditions on the Mechanical Properties of Polylactide-Based Composites

Polylactide-based composites filled with waste fillers due to their sustainability are a subject of many current papers, in which their structural, mechanical, and thermal properties are evaluated. However, few studies focus on their behavior in low temperatures. In this paper, dynamic and quasi-static mechanical properties of polylactide-based composites filled with 10 wt% of linseed cake (a by-product of mechanical oil extraction from linseed) were evaluated at room temperature and at -40 °C by means of dynamic mechanical analysis (DMA), Charpy's impact strength test and uniaxial tensile test. It was found that the effect of plasticization provided by the oil contained in the filler at room temperature is significantly reduced in sub-zero conditions due to solidification of the oil around -18 °C, as it was shown by differential scanning calorimetry (DSC) and DMA, but the overall mechanical performance of the polylactide-based composites was sufficient to enable their use in low-temperature applications.

Improving the Toughness and Thermal Resistance of Polyoxymethylene/Poly(lactic acid) Blends: Evaluation of Structure-Properties Correlation for Reactive Processing

The study focuses on the development of polyoxymethylene (POM)/poly(lactic acid) (PLA) blends with increased impact and thermal resistance. The study was conducted in two phases; in the first part, a series of unmodified blends with PLA content of 25, 50, and 75 wt.% was prepared, while the second part focused on the modification of the PLA/POM (50/50) blends. An ethylene/butyl acrylate/glycidyl methacrylate terpolymer (E/BA/GMA) elastomer (EBA) was used to improve the impact strength of the prepared blends, while reactive blending was used to improve interfacial interactions. We used a multifunctional epoxy chain extender (CE) as the compatibilizer. Static tensile tests and notched Izod measurement were used to evaluate the mechanical performance of the prepared samples. The thermomechanical properties were investigated using dynamic mechanical thermal analysis (DMTA) analysis and heat deflection temperature (HDT)/Vicat softening temperature (VST) methods. The crystallinity was measured using differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXS) measurements, while the rheology was evaluated using a rotational rheometer. The paper also includes a structure analysis performed using the SEM method. The structural tests show partial miscibility of the POM/PLA systems, resulting in the perfect compatibility of both phases. The impact properties of the final blends modified by the EBA/CE system were found to be similar to pure POM resin, while the E modulus was visibly improved. Favorable changes were also noticeable in the case of the thermomechanical properties. The results of most of the conducted measurements and microscopic observations confirm the high efficiency of the reaction for PLA as well as for the modified POM/PLA mixtures.

The effect of the addition of a slip agent on the rheological properties of polyethylene: off-line and in-line measurements

The article describes an investigation into the effect of a slip agent on the rheological properties of low-density polyethylene. As a slip modifier, oleamide was used in the amounts of 0.5, 1.0, 2.0, 3.0 and 4.0 wt.%, respectively. The process of polymer modification was carried out in a twin-screw extrusion process. The effect of the slip agent on the mass flow rate index was determined. The specific plasticisation energy of the modified polymer was also assessed based on the change in the torque of a batch mixer. The assessment of the effect of the addition of oleamide on the change in the flow and viscosity curves was made using an off-line (plastometer) and an in-line (extruder rheometer) measuring technique. The rheological parameters were determined based on the Ostwald-de-Waele power law model. The operation of the plastometer was brought closer to the principles of operation of the capillary rheometer by applying variable piston loading. In in-line measurements, an extrusion head with replaceable cylindrical dies was used. Using two rheological measuring techniques made it possible to determine the low-density polyethylene viscosity variations and the values of flow power law index (n) and consistency factor (K) in a wide shear rate range.