This paper reviews the current trends in replacing commonly used plasticizers in poly(vinyl chloride), PVC, formulations by new compounds with reduced migration, leading to the enhancement in mechanical properties and better plasticizing efficiency. Novel plasticizers have been divided into three groups depending on the replacement strategy, i.e., total replacement, partial replacement, and internal plasticizers. Chemical and physical properties of PVC formulations containing a wide range of plasticizers have been compared, allowing observance of the improvements in polymer performance in comparison to PVC plasticized with conventionally applied bis(2-ethylhexyl) phthalate, di-n-octyl phthalate, bis(2-ethylhexyl) terephthalate and di-n-octyl terephthalate. Among a variety of newly developed plasticizers, we have indicated those presenting excellent migration resistance and advantageous mechanical properties, as well as those derived from natural sources. A separate chapter has been dedicated to the description of a synergistic effect of a mixture of two plasticizers, primary and secondary, that benefits in migration suppression when secondary plasticizer is added to PVC blend.

Low solubility of terephthalic acid in common solvents makes its industrial production very difficult and not environmentally benign. Ionic liquids are known for their extraordinary solvent properties, with capability to dissolve a wide variety of materials, from common solvents to cellulose, opening new possibilities to find more suitable solvents for terephthalic acid. This work presents studies on the solubility of terephthalic acid in ionic liquids, and demonstrates that terephthalic acid is soluble in ionic liquids, such as 1-ethyl-3-methylimidazolium diethylphosphate, 1-butyl-3-methylimidazolium acetate, and dialkylimidazolium chlorides up to four times higher than in DMSO. Additionally, the temperature effect and correlation of ionic liquid structure with solubility efficiency are discussed.

Inexpensive Brønsted acidic ionic liquids based on trimethylamine and sulfuric acid are proposed as both solvents and catalysts in the synthesis of alternative plasticizer bis(2-ethylhexyl) terephthalate, which has a broad spectrum of applications in plasticization processes. The utilization of 50 mol % of Brønsted ionic liquid led to the full conversion of terephthalic acid after 8 h of reaction at 120 °C. Additionally, a 100% selectivity of bis(2-ethylhexyl) terephthalate was obtained. The advantage of the presented reaction system is based on the formation of a biphasic system during the reaction. The bottom phase consists of an ionic liquid and water, and the upper phase is created by the ester and unreacted alcohol. This phenomenon helps overcome the equilibrium of the reaction and drives it towards a high yield of product. The presented new approach is proposed as a safe, cost-effective, and alternative method to conventional processes with organometallic compounds that, in turn, leads to greener and a more economically viable technology.

Alkyl lactates are produced from lactic acid via esterification, and are used in the production of plastics, paints, solvents and detergents. In the pursuit of an inexpensive, industry-suitable catalyst for this reaction, the application of protic ionic liquids based on nitrogen base and sulphuric acid is proposed. The ionic liquid was synthesised via a simple reaction of triethylamine and a threefold molar excess of sulphuric acid. Water was added to remove the heat of the reaction. Next, the reaction conditions for the model esterification of 2-ethylhexanol with lactic acid without additional solvent were optimised. Exceptionally mild conditions, i.e., a twofold molar excess of alcohol to lactic acid with the addition of an ionic liquid in a catalytic amount (15 mol%) at 60 °C, resulted in high yields of ethyl and 2-ethylhexyl lactates (96–97%). The driving force of this reaction is the production of a biphasic system with immiscible ester during the reaction. This phenomenon makes it possible to overcome the reaction equilibrium. Using an inexpensive ionic liquid, which could be recycled up to five times without diminution in conversion or selectivity, leads to both a greener and a more economically-viable process.

As a result of strict regulations of phthalate plasticizers, alternative non-phthalate forms are desired and increasingly used. This work presents a synthetic method for alternative plasticizers (dialkyl succinates and adipates) via esterification of succinic and adipic acid with alcohols: butan-1-ol and 2-ethylhexan-1-ol. Ionic liquids were synthesized by the reaction of triethylamine with over-equimolar (1:2.7) amounts of sulfuric(VI) acid, which were used as an acidic catalyst and solvent. The two-phase liquid–liquid system was formed during the reaction due to immiscibility of the esters with the ionic liquid. This phenomenon is a driving force of this process, shifting the equilibrium toward the product formation. As a result, dialkyl succinates and adipates were obtained in high yields (99%) and selectivities (>99%), under mild reaction conditions at 70–80 °C and using a 4:1 molar ratio of alcohol to acid and 15 mol% of catalyst. The catalyst was recycled 10 times without any loss of activity. This alternative method is highly competitive: it involves a simple procedure for product isolation as well as a high yield and purity of the resulting esters. These advantages make this method sustainable and promising for industrial applications.

Granular fertilizers (especially those based on ammonium nitrate (AN)) tend to agglomerate during storage. The aims of this research were to develop effective anti-caking coatings for ammonium nitrate fertilizers while improving the quality of fertilizers and to optimize the composition of effective anti-caking coatings. The influence of the composition of the prepared organic coatings on the effectiveness of preventing the caking of fertilizers was studied by response surface methodology (RSM) using Box–Behnken design (BBD). Additionally, the effect of the developed anti-caking agents on the quality of fertilizers was determined by measuring the crushing strength of the granules. The prepared coatings included fatty amine, stearic acid, surfactant, and paraffin wax. Gas chromatography–mass spectrometry (GC–MS) was used to analyze these coatings. The morphology of the fertilizers were examined by scanning electron microscopy (SEM). Composition studies, based on statistical assessment, showed the coating components had a varying influence on preventing the caking of fertilizers after granulation and after 30 days of storage. The results demonstrated that increasing the content of fatty amines and reducing surfactant in the composition of coating had positive effects on caking prevention. In this study, more effective and economically viable anti-caking coatings were developed. In addition, the present work could serve as a basis to further improve anti-caking coatings.

Immobilized poly(ethylene glycol) (PEG 600-PS) was used as an effective phase-transfer catalyst for the synthesis of hydroxypivaldehyde from isobutyraldehyde (IBA) and formaldehyde in the presence of an inorganic base. Studies on the influence of the parameters on the course of the reaction in a batch reactor showed that the use of the PEG 600-PS catalyst allowed one to obtain HPA with high efficiency (IBA conversion >96%, selectivity >98%) in a relatively short time and under mild conditions (2 h, 40 °C). The developed method enables easy separation of the post-reaction mixture by simple phase separation, and the immobilized catalyst can be separated by filtration and then used five times without a loss in its activity. The high activity and stability of the catalyst was also confirmed in a test carried out in a flow reactor.

Neopentyl glycol (NPG) is a precursor for the manufacture of many valuable products of industrial importance such as polyester, polyurethane and alkyd resins, synthetic lubricants, hydraulic fluids, drugs, etc. The structure of NPG provides the resins with excellent hydrolytic stability, resistance to weather conditions, good flexibility-hardness balance, and outstanding functional properties. The paper presents a literature review on the development of methods for NPG preparation, focusing primarily on the synthesis of NPG by hydrogenation of hydroxypivaldehyde, which is obtained by the crossed aldol condensation of isobutyraldehyde and formaldehyde. Preparation of the substrates, catalysts, technical and apparatus solutions, and NPG purification were discussed.