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The increasing accumulation of synthetic plastic waste in oceans and landfills, along with the depletion of non-renewable fossil-based resources, has sparked environmental concerns and prompted the search for environmentally friendly alternatives. Biodegradable plastics derived from lignocellulosic materials are emerging as substitutes for synthetic plastics, offering significant potential to reduce landfill stress and minimise environmental impacts. This study highlights a sustainable and cost-effective solution by utilising agricultural residues and invasive plant materials as carbon substrates for the production of biopolymers, particularly polyhydroxybutyrate (PHB), through microbiological processes. Locally sourced residual materials were preferred to reduce transportation costs and ensure accessibility. The selection of suitable residue streams was based on various criteria, including strength properties, cellulose content, low ash and lignin content, affordability, non-toxicity, biocompatibility, shelf-life, mechanical and physical properties, short maturation period, antibacterial properties and compatibility with global food security. Life cycle assessments confirm that PHB dramatically lowers CO₂ emissions compared to traditional plastics, while the growing use of lignocellulosic biomass in biopolymeric applications offers renewable and readily available resources. Governments worldwide are increasingly inclined to develop comprehensive bioeconomy policies and specialised bioplastics initiatives, driven by customer acceptability and the rising demand for environmentally friendly solutions. The implications of climate change, price volatility in fossil materials, and the imperative to reduce dependence on fossil resources further contribute to the desirability of biopolymers. The study involves fermentation, turbidity measurements, extraction and purification of PHB, and the manufacturing and testing of composite biopolymers using various physical, mechanical and chemical tests.

In the denim industry, enzyme washing and its combination with stone washing are generally used to get the desired worn-out look. However, these conventional methods include high water, energy and time consumption. Nowadays, laser fading, which is a computer-controlled, dry, ecological finishing method, is preferred in the denim fading process. The purpose of this study is to observe the effects of chemical pretreatment applications on laser-faded denim fabric in terms of color and mechanical properties. To eliminate the enzyme washing process in denim fading and to minimize the disadvantages of laser fading, such as decreased mechanical properties and increased fabric yellowness, various chemical pretreatment applications were applied to the denim fabric before laser fading, followed by simple rinsing instead of enzyme washing.

Two different indigo-dyed, organic cotton denim fabrics with different unit weights were exposed to pretreatment processes and then laser treatment, followed by simple rinsing. Polysilicic acid, boric acid, borax and bicarbonate were used for pretreatment processes, and laser treatment was carried out under optimized laser parameters (40 dpi resolution and 300 µs pixel time). Tensile strength was tested, and color values (CIE L*, a*, b*, ΔE*, C* and h), color yield (K/S), yellowness and whiteness indexes were measured to identify the color differences.

Before laser fading, 30 g/L and 40 g/L polysilicic acid pretreatments for sulfur-indigo-dyed fabric and a mixture of 10 g/L boric acid and 10 g/L borax pretreatments for the fabric only indigo-dyed were recommended for the laser fading with sufficient mechanical properties and good color values.

With the chemical pretreatments defined in this study, it was possible to reduce yellowness and maintain the mechanical properties after laser fading, thus minimizing the disadvantages of laser treatment and also eliminating enzyme washing.

A sophisticated computer monitoring and control system developed by BL Technology Ltd for car body pretreatment processes, and later adopted for the Jaguar Car Body production line at Castle Bromwich, is now available to other manufacturers worldwide from Pyrene Chemical Services Ltd, who have been granted marketing rights.

Large bore pipelines used for oil, natural gas and other utility distribution purposes are commonly buried underground or run beneath the sea, where they are expected to remain for up to 50 years. The environment is potentially very corrosive, so that protection against corrosion attack is commonly provided jointly by a fusion bonded epoxy powder coating applied externally and by an impressed cathodic electric potential. For many years, pipe coaters have been plagued by a phenomenon known as cathodic disbondment, i.e. adhesion failure of the coating, induced by the electric potential spreading from areas where the coating has been mechanically damaged. Pyrene has now solved this problem, to the particular delight of British Pipe Coaters Ltd.

A new system that enables the U.S. Army's AH‐64A attack helicopter to transmit or receive target acquisition information using other aircraft or ground stations is being proposed by McDonnel Douglas.

Manufacaturers who always wanted to achieve the superior paint finish on metal components that a conversion coating pretreatment provides, but who thought that they had neither the capital nor the room for a plant, can now benefit from the low‐cost QUBE system being jointly launched by Walterisation (UK) Limited and Teijo (UK) Limited. QUBE comprises a compact single‐cabinet spray pretreatment plant and the necessary speciality chemicals. The plant is manufactured by the Finnish Idea Machine company and has been proven in the demanding Scandinavian metal finishing market. Developed from Walterisation's fifty years experience in the pretreatment field, the chemicals will be supplied to suit the application and type of metal to be treated.

The performance of different pretreatment‐primer systems for hot‐dip galvanized (HDG) and Galfan coated steel has been studied. The materials were pretreated with three pretreatment processes; an alkaline oxide pretreatment with either a chromate or a zirconium based post‐rinse, and a zinc phosphating pretreatment. After the pretreatment, the panels were coated with four commercially available primers. The chemically treated substrates were characterized by using ESCA and GD‐OES, and the cured paint films by using FTIR. Paint adhesion of primed panels was determined with a combined cross‐cut and impact test and also with the NMP test. Formability of the panels was tested by T‐bend test and corrosion resistance with a cyclic prohesion test. According to the prohesion test results, primed Galfan coated panels have better edge corrosion resistance than primed HDG panels. Test results also show that the effect of pre‐treatment is not as significant for the corrosion resistance as the effect of primer. However, in the case of zinc phosphated samples, excellent synergistics between the pretreatment and two of the primers was detected.

FOR whatever reason — general wear and tear, change of livery, or metallographic inspection procedures — aircraft are repainted. This is a fact of life that many would wish fictional, since the job is not one which could be described as the cleanest in the world, nor the most pleasant. A typical refurbishment process sequence could be simplified into eight steps: paint stripping; rinsing; cleaning; rinsing; pre‐treatment; rinsing; drying and repainting. This short article deals only with one aspect of the sequence — the pretreatment.

The purpose of this paper is to investigate straw modification by chemical degradation generated by two forms of pretreatment, using citric acid in an autoclave and urea solution with sodium hydroxide at low temperature.

The material was digested and compared in biodigester reactors lined with natural straw, straw pretreated with citric acid, straw pretreated with urea and NaOH, and straw subjected to both the pretreatments. The amount of straw has been delimited to 0, 2.5, 5, 7.5 and 10 percent v/v, and used 20 percent v/v inoculum in all reactors, consisting of 30 percent v/v poultry litter and 70 percent swine wastewater (SW). The experiment was conducted in an incubator kept in mesophilic conditions (35°C).

The results indicate significant change in the studied material, with degradation of lignin as well as hemicellulose and cellulose exposed to further hydrolysis. Spectrophotometric methods were used for monitoring degradation. These methods were efficient in monitoring changes caused by the treatments. When the proposed pretreatments are applied to sugarcane straw, there is a significant gain in biogas production (L g VSR⁻¹). The most appropriate rates for higher methane production in the pretreatments are 2.5 and 5 percent straw-SW. The best results for the anaerobic digestion of sugarcane straw were obtained by pretreating it with citric acid.

This paper shows a new use for the sugarcane straw waste after being pretreated with acid or base for the coproduction of biogas.

Low temperature metal surface cleaning and phosphating processes developed by Pyrene Chemical Services Ltd., are said to be saving £8,370 per year in energy costs at the Bradford factory of International Harvester Co. of Great Britain Ltd. Pyrene Bonderite 299 low temperature phosphating and Pyroclean 499 low temperature cleaner were introduced into the pretreatment line a year ago after careful test runs to establish what the potential cost‐savings would be. These savings have been confirmed in practice.