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•Structural foams are prepared from highly reactive plant-oil derived epoxy resins.•A multi-techniques approach is proposed for optimizing the resin formulation.•Potassium bicarbonate ...is used as innocuous but efficient blowing agent.•The foams present Tg higher than 80 °C and density lower than 0.05 g/cm3.•All these properties make the materials potential candidates for industrial application.
This paper is devoted to the description of the scientific method used for developing biobased structural foams derived from highly reactive epoxy resins. The chemical formulations were obtained from the mixing of two epoxidized plant oil-derivates (epoxidized linseed oil ELO and glycerol triglycidyl ether commonly named epoxidized glycerol EG) with an anhydride hardener and a non-toxic foaming agent. The optimization of the composition was achieved by studying the influence of many parameters such as the proportion of each epoxy molecule in the reactive formulation, the exact nature of the hardener or foaming agent retained by the use of different complementary experimental techniques. For instance, the reactivity of four cyclic anhydride compounds with ELO was investigated by differential scanning calorimetry and rheometry in dynamic or kinetic mode. Two different blowing agents were initially retained for the preparation of foams and their respective density and mechanical properties were evaluated and compared. The proportion of each epoxy molecule (ELO and EG) was also tuned to achieve a good equilibrium between the gelation and foaming mechanisms within a few minutes. The definition of an optimized composition made it possible the production of rigid foams using a short production time (i.e. lower than 3 min). These foams were characterized by a glass transition temperature close higher than 80 °C and an apparent density comprised between 0.05 and 0.08 g/cm3. Their specific mechanical properties were judged convenient for a possible valorisation as lightweight structural material.
The harmful effects of wear can be reduced through proper lubrication of the frictional parts. When exposed to excessive loads, the lubricant film is displaced from the surfaces, and even the ...adhesive lubricant layer may rupture. Additives known as Extreme Pressure (EP) are frequently incorporated into lubricants to minimise wear and avert seizures under high temperature and pressure. Mechanistically, these additives generate a film on the surface through chemisorption. These additives are extensively applied in various lubricants, with the largest quantities being employed in metalworking fluids and lubricating greases. Sulfurized vegetable oils and their derivates can be used as EP additives for lubricants. To conduct the investigations, sulfurized additives were synthesized using different vegetable-based oils and fatty acid esters, and alpha-olefins. In this study, the Four-ball test results were compared to gain a more accurate comprehension of how various raw-material-based additives influence wear and friction. The goal was to select raw materials that could be used with favorable results for the production of EP additives. The objective was to achieve a minimum Four-ball weld load parameter of 2000 N. The experiments revealed that the functional impacts of the synthesized samples are dependent on the type of raw materials employed. Based on the experimental data and the stated criteria, the examined raw materials were found to be suitable for the synthesis of EP additives.
•This paper addresses the pipeline scheduling of heavy oil derivatives.•This paper is the first to cope with heating constraints and sharing of tanks.•A decomposition procedure based on MILP models ...and heuristics is presented.•The developed approach is tested using a real-world scenario (pipeline tree).
This paper presents a novel approach to aid the operational decision-making of scheduling activities in a real-world pipeline, transporting heavy oil derivatives, which are products of less aggregate value, such as fuel oils, e.g. marine fuel. These products present special characteristics that influence their transport as the impossibility of being transferred at room temperature, due to their viscosity, or the use of shared tanks for different products. Thus, during the transport of such products, the entire pipeline network (and the tanks) must be maintained heated during all the pumping process. Such characteristics imply that a specific model oriented to this type of problem must be developed. The approach proposed in this work develops a decomposition procedure that uses a sequence of mathematic programming models and heuristics to solve the problem in hand. The proposed approach is tested using a real-world scenario, composed of a pipeline tree system.
In this study, the effect of two boric acid concentrations (1% and 2%) and four derivates of tall oil with varying chemical composition were tested separately and in combination. The tall oil ...derivates were chosen in a way that they consist of different amounts of free fatty, resin acids and neutral compounds. Decay tests using two brown rot fungi (
Postia placenta and
Coniophora puteana) were performed on both unleached and leached test samples. Boric acid showed a low weight loss in test samples when exposed to fungal decay before leaching, but no effect after leaching. The tall oil derivates gave better efficacy against decay fungi compared to control, but are not within the range of the efficacy needed for a wood preservative. Double impregnation with boric acid and tall oil derivates gave synergistic effects for several of the double treatments both in unleached and leached samples. In the unleached samples the double treatment gave a better efficacy against decay fungi than tall oil alone. In leached samples a better efficacy against brown rot fungi were achieved than in samples with boron alone and a nearly similar or better efficacy than for tall oil alone. Boric acid at 2% concentration combined with the tall oil derivate consisting of 90% free resin acids (TO-III) showed the best performance against the two decay fungi with a weight loss less than 3% after a modified pure culture test.
