Amide/Amino-Based Functional Additives for Lubricants: Structure, Antimicrobial Activity and Wear Resistance.

The lubricating properties of the lubricants were tested under boundary friction conditions; it was found that the surface-active additives had reduced the wear mark and thus the value of the Goz/40 parameter (limiting load of wear). The introduction of a surfactant containing amide compounds into the oils and greases was highly effective in slowing down the oxidation process. Lubricants containing mono-15 ([3-(N,N,N-dimethylbuthylamine)propyl]hexadecanamide chloride) and 15-4-15 (tetramethylene-bis [3-(N,N,N-dimethylamine)propyl]hexadecanamide) additives were characterised by higher oxidation stability compared to the unmodified lubricants. Both of the analysed substances showed bactericidal properties against Staphylococcus aureus and Salmonella enteritica. Tests of antibacterial activity in the lubricants with the addition of mono-15 and 15-4-15 confirmed that these lubricants can be considered bactericidal against Gram-positive and Gram-negative bacteria.

Barrier Dispersion-Based Coatings Containing Natural and Paraffin Waxes.

Petroleum, synthetic, and natural waxes have been used as hydrophobic bases for dispersions intended for use as barrier coatings for packaging paper. Oil-in-water dispersions with alkaline pH were prepared by a two-step homogenization procedure containing paraffin wax, with various characteristics, the Fischer-Tropsch synthesis product or beeswax. The size of the dispersed particles determined by dynamic light scattering depended on the type of hydrophobic base used and was in the range of 350-440 nm. The ability of dispersion particles in aggregation driven by electrostatic attraction, evaluated by Zeta potential analysis by electrophoretic light scattering, was from -26 to -50 mV. Static multiply light scattering was used for 30 days of stability assessment and helped to select the dispersion with a Sarawax SX70 wax base as the most stable. Dispersions were further used for coating the backing of kraft paper by the Meyer rod method. Coated paper with an applied coating of 6 g/m2 had very good hydrophobic properties (Cobb60 < 4 g/m2), sufficient strength properties, and air permeation, which enabled its application as a packaging material. The dispersions based on Sarawax SX70 wax were evaluated as the best coating for Mondi ProVantage Kraftliner 125 g/m2 backing paper. Good hydrophobic properties and strength properties indicate the possibility of using the SX70-based wax dispersion coating as a replacement for PFAS coatings in some applications.

Cancer and occupational exposure to pesticides: a bibliometric study of the past 10 years.

Occupational exposure to pesticides has been identified as a major trigger of the development of cancer. Pesticides can cause intoxication in the individuals who manipulate them through either inhalation, ingestion, or dermal contact. Given this, we investigated the association between the incidence of cancer and occupational exposure to pesticides through a bibliometric analysis of the studies published between 2011 and 2020, based on 62 papers selected from the Scopus database. The results indicated an exponential increase in the number of studies published over the past decade, with most of the research being conducted in the USA, France, India, and Brazil, although a further 17 nations were also involved in the research on the association between cancer and pesticides. The principal classes of pesticides investigated in relation to their role in intoxication and cancer were insecticides, herbicides, and fungicides. The types of cancer reported most frequently were multiple myeloma, bladder cancer, non-Hodgkin's lymphoma, prostate cancer, leukemia, and breast cancer. Despite the known association between pesticides and cancer, studies are still relatively scarce in comparison with the global scale of the use of these xenobiotic substances, which is related to the increasing demand for agricultural products throughout the world.

Spectroscopic Methods in the Evaluation of Modified Vegetable Base Oils from Crambe abyssinica.

Raw vegetable oil from Crambe abyssinica was subjected to oxidative treatment to enhance its viscosity. The oxidation processes were carried out in the presence of N-hydroxyphthalimide with or without supercritical CO2 as a solvent. Four spectroscopic techniques (Raman, UV-VIS, FT-IR, NMR) were applied to assess the chemical changes taking place during the oxidation. Raman and NMR spectroscopy proved best in the assessment of the chemical transformations leading to increased viscosity of the modified vegetable oil.

Designing Lubricating Properties of Vegetable Base Oils.

Lubricants that are based on renewable raw materials have drawn increased attention in various applications, especially those related to the food industry. Due to the high requirements of environmental protection, there is a need to develop biodegradable base oils that are environmentally friendly and do not contain harmful components. The objective of the research was to obtain a base oil with a certain viscosity and certain desired lubricating properties. Base oils were obtained from Crambe abyssinica oil by means of blending with synthetic oil and oxidation. The oxidation processes were carried out in the presence of N-hydroxyphthalimide with or without CO2 as a solvent. As a final result of this study, oil bases meeting the viscosity requirements and showing suitable lubricating properties were obtained. The Raman spectra of the obtained oils were evaluated.

Selective Synthesis of Polyoxyethylene-Polyoxypropylene Block Copolymer (Poloxamer) Fatty Acid Monoesters Over Homogeneous Organotin Catalyst.

The synthesis of selected polyoxyethylene-polyoxypropylene block copolymer (poloxamer) fatty acid monoesters is presented. Organotin homogeneous catalyst Sn bis(2-ethylhexanoate) effectively catalyzed the esterification reaction of (EO)-(PO)-(EO) block copolymer (poloxamer) with fatty acids. The reaction proceeded in high yield and high selectivity to monoesters. Content of diesters in final products was below 1 wt%. The new protocol opened up a high yield and high selective method for the synthesis of poloxamer fatty acid monoesters. These products are potentially interesting for industrial applications, e.g. in lubricants, cosmetics and, in particular, as potential emulsifying agents compatible with hydrocarbon bases, such as paraffin.