Synthesis and characterisation of alkyd resins with glutamic acid-based monomers

Preparation of new surface coating based on modified oil-based polymers blended with ZnO and CuZnO NPs for steel protection

In our paper, we have synthesized modified PEA and alkyd resin by replacing the new source of polyol (SDEA) which was confirmed by different analyses such as IR, and 1HNMR spectra. A series of conformal, novel, low-cost, and eco-friendly hyperbranched modified alkyd and PEA resins were fabricated with bio ZnO, CuO/ZnO) NPs through an ex-situ method for mechanical and anticorrosive coatings. The synthesized biometal oxides NPs and its composite modified alkyd and PEA were confirmed by FTIR, SEM with EDEX, TEM, and TGA, and can be stably dispersed into modified alkyd and PEA resins at a low weight fraction of 1%. The nanocomposite coating was also subjected to various tests to determine their surface adhesion, which ranged from (4B-5B), physico-mechanical characteristics such as scratch hardness, which improved from < 1.5 to > 2 kg, gloss (100-135) Specific gravity (0.92-0.96) and also chemical resistance test which passed for water, acid, and solvent except alkali, was poor because of the hydrolyzable ester group in the alkyd and PEA resins. The anti-corrosive features of the nanocomposites were investigated through salt spray tests in 5 wt % NaCl. The results indicate that well-dispersed bio ZnO and CuO/ZnO) NPs (1.0%) in the interior of the hyperbranched alkyd and PEA matrix improve the durability and anticorrosive attributes of the composites, such as degree of rusting, which ranged from 5 to 9, blistering size ranged from 6 to 9, and finally, scribe failure, which ranged from 6 to 9 mm. Thus, they exhibit potential applications in eco- friendly surface coatings. The anticorrosion mechanisms of the nanocomposite alkyd and PEA coating were attributed to the synergistic effect of bio ZnO and (CuO/ZnO) NPs and the prepared modified resins are highly rich in nitrogen elements, which might be regarded as a physical barrier layer for steel substrates.

Triple Benefits of Cardanol as Chain Stopper, Flame Retardant and Reactive Diluent for Greener Alkyd Coating

Cardanol, a waste from the food industry and widely produced (1 Mt/y), has been used as a chain stopper during the polycondensation of short oil alkyd resins in order to replace benzoic acid. Then, phosphorylated cardanol has been added in order to both reduce solvent content and bring flame-retardant (FR) properties to the alkyd resins. The renewable carbon content of the formulations has been increased up to 23%. The impact of the introduction of phosphorylated cardanol molecules on the drying time and flexibility has been studied as well as the thermal and flame-retardant properties by differential scanning calorimeter, thermogravimetric analysis and pyrolysis-combustion flow calorimeter. The most effective flame-retardant coating that was associated with excellent FR properties and excellent coating properties has been obtained with phosphate-cardanol added at 2%wt of P. Indeed, the film properties were closed to the classical alkyd resin, the solvent content was reduced by 50% and the pHRR decreased by 42% compared to the reference alkyd resin.

Preparation and evaluation of high-performance modified alkyd resins based on 1,3,5-tris-(2-hydroxyethyl)cyanuric acid and study of their anticorrosive properties for surface coating applications

By partially substituting 1,3,5-tris-(2-hydroxyethyl) cyanuric acid for glycerol as the polyol, new modified alkyd resins having a wide range of oil length and hydroxyl content were produced. FT-IR, 1H NMR, acid and iodine values, and other characterization techniques were used to confirm the chemical compositions of the modified alkyd resins. The drying qualities of the alkyd resins synthesized were significantly enhanced by adding a greater quantity of freshly prepared polyol and excess –OH, along with improvements in flexibility, gloss measurement, gloss measurement, and scratch hardness, in comparison to unaltered alkyd resin (blank). The corrosion resistance of dried coated steel panels was examined using a salt spray test. By using a specifically designed modified alkyd resin as a binder, the corrosion resistance of painted steel panels was improved. The addition of the new polyol, which contains nitrogen components, as well as the alkyd resins that provide strong adherence to the steel surface, may be responsible for such an improvement.

Preparation of new modified antimicrobial alkyd resin based on benzo[b]thiophene derivative as source of polyol for surface coating applications

Purpose

This paper aims to prepare new modified alkyd resins and use it as an antimicrobial binder for surface coating applications.

Design/methodology/approach

Various modified alkyd resins were prepared by partial replacement of 3,6-dichloro benzo[b]thiophene-2-carbonyl bis-(2-hydroxy ethyl)-amide as a source of polyol with glycerol and confirmed by acid value, FT-IR, 1H-NMR. The modified alkyd resins were covering a wide range of oil lengths and hydroxyl content (0%, 10%, 20% and 30% excess-OH). The antimicrobial activity of the prepared alkyds was also investigated. The coatings of 60 ± 5 µm thickness were applied to the surface of glass panels and mild steel strips by means of a brush. Physico-mechanical tests, chemical resistance and antimicrobial activities were investigated.

Findings

The obtained results illustrate that the introduction of benzo[b]thiophene derivative as a modifier polyol within the resin structure improved the film performance and enhanced the physico-mechanical characteristics, chemical resistance and the antimicrobial activities.

Practical implications

The modified alkyd resins can be employed as antimicrobial binders in paint compositions for a variety of surfaces, particularly those that are susceptible to a high number of bacteria.

Originality/value

Modified alkyd resins based on antimicrobial heterocyclic compounds have the potential to be promising in the manufacturing of antimicrobial coatings and development of paints, allowing them to function to prevent the spread of microbial infection, which is exactly what the world requires at this time. Also, they can be applied in different substrates for industrial applications.

Protein-Rich Biomass Waste as a Resource for Future Biorefineries: State of the Art, Challenges, and Opportunities

Protein-rich biomass provides a valuable feedstock for the chemical industry. This Review describes every process step in the value chain from protein waste to chemicals. The first part deals with the physicochemical extraction of proteins from biomass, hydrolytic degradation to peptides and amino acids, and separation of amino acid mixtures. The second part provides an overview of physical and (bio)chemical technologies for the production of polymers, commodity chemicals, pharmaceuticals, and other fine chemicals. This can be achieved by incorporation of oligopeptides into polymers, or by modification and defunctionalization of amino acids, for example, their reduction to amino alcohols, decarboxylation to amines, (cyclic) amides and nitriles, deamination to (di)carboxylic acids, and synthesis of fine chemicals and ionic liquids. Bio- and chemocatalytic approaches are compared in terms of scope, efficiency, and sustainability.