Miscellaneous Additives and Vegetable Oils

Crawford, J. Selwyn; Psaila, Alexander F.; Orszulik, Stefan T.

doi:10.1023/b105569_6

Cited by 6 publications

(10 citation statements)

References 1 publication

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“…The adsorption energy of this monolayer ranges from 10 to 30 kJ mol -1 [4] and corresponds to a hydrogen bond. The molecular chains of glycerol esters in the mono and multi layers are stabilized by van der Waals cohesion forces, which makes the film more resistant to stress in comparison with the film formed by mineral-based release agents [8]. Differing degrees of separation of the surfaces occur depending on the velocity of the concrete flow, the viscosity of the oil, the temperature and pressure (load) to which the film is subjected, and the surface structure of the materials in relative motion [4].…”

Section: Discussionmentioning

confidence: 99%

Laboratory and field performance of biodegradable release agents for hydraulic concrete

et al. 2015

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Raw vegetable oils and their emulsions have been used as biodegradable release agents for concrete. However, there is no scientific explanation linking the chemical composition to their release performance. The present study was divided into two phases. In the first phase, different vegetable oils with varying degrees of refinement were chemically characterized by middle range Fourier transform infrared spectroscopy (Mid-FTIR), and their viscosities were measured. For comparison purposes, two commercial release agents based on mineral oil were used. In the second phase, emulsions containing bleached soybean oil, water and some emulsifiers were prepared. The performance of the oils and emulsions as demolding agents in steel/concrete interfaces was measured by visual rating, image analysis and bond strength. The results indicate that almost all of the vegetable oils showed better performance than that of the two mineral oil-based agents, which is explained by the higher affinity of glycerol esters for metal surfaces and higher intermolecular interactions. The Mid-FTIR espectrum analysis indicates that oils having larger absorption areas under the curve at the methylene group exhibit better performance as release agents. In addition, the Mid-FTIR analysis allowed identification of the main molecular groups and differentiation between oil samples. In the second phase, the water/oil emulsion stabilized with organophilic clay performed the best. In addition to the lubricating effect of the emulsion, the better performance was also due to the saponification reaction between the acylglycerides and the Ca(OH) 2 . The tangential adhesion was reduced to approximately 64 % compared to that of a mold without a release agent.

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Section: Discussionmentioning

confidence: 99%

Laboratory and field performance of biodegradable release agents for hydraulic concrete

et al. 2015

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“…Foams in lubricants are due to trapped air molecules in the oil, which can gather together to form air bubbles (gaseous polyhedral cells partitioned by light films of liquid) when the oil is perturbed or agitated. They are also largely contributed by surface active (extreme pressure) additives and detergents, which do strongly affect the surface tension of any oil when added during blending, giving room for formation of air bubbles below the oil surface .…”

Section: Lubricant‐protective Agents and Vegetable Oilsmentioning

confidence: 99%

“…In ASAs, foaming can increase the compressibility of the fluid, resulting in shock absorber failure . Although VOs generally have good resistance against foaming, antifoam agents (AFAs) like liquid silicone polymers (polydimethylsilicones), polydimethylsiloxanes (21 mN/m surface tension), fluorosilicones (<21 mN/m surface tension), polyalkoxyamines, polyethylene glycols, dimethyl‐siloxane, alkyl‐methacrylate and alkyl‐acrylates, which can reduce the surface tension of foam cells, particularly at the contact points called the Plateau borders, where the existence of bent locations of low‐pressure capable of causing liquid drainage may still be required. They can control the foam formation in the oil, especially in shock absorber fluid where net zero foaming is desired.…”

Section: Lubricant‐protective Agents and Vegetable Oilsmentioning

confidence: 99%

Suitable additives for vegetable oil‐based automotive shock absorber fluids: an overview

Bongfa

Samion

Hamid

et al. 2016

Lubrication Science

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Formulation of a cost-effective, high-performance and eco-friendly lubricant, largely depends on the base oil quality, then the selection of suitable additives and their proportions. Vegetable oils, identified to be eco-friendly, renewable, future-available and cost-effective treasures for lubricant formulation, apart from processing, will rely much on suitable additives to meet the performance requirements for automotive shock absorber (ASA) fluids. Additives that will guarantee performance, longevity and eco-friendliness of formulated vegetable-based functional fluids have to be uncommonly effective, resistant to depletion, non-toxic and highly biodegradable. Their selection in these regards will require skills and experience, which will harness the various arms of synergism as effective tools to succour the known weaknesses of the base oil. This is a review on additives that could be used in formulation of vegetable oil-based (ASA) fluids. The outcome shows that there are customary and novel additives that are suitable for formulating vegetable oil-based ASA fluids.

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“…It is well known that lubricant additives are practically used to improve the tribological characteristic of the base stock, especially at some rigorous conditions [1,2]. But most traditional lubricant additives contain harmful components, such as Cl, P, and some heavy metals.…”

Section: Introductionmentioning

confidence: 99%

“…But most traditional lubricant additives contain harmful components, such as Cl, P, and some heavy metals. To protect the nature, current lubricant additive research sees a favoring tendency to explore new environment-friendly and multifunctional additives [2][3][4][5][6]. On the other hand, compared with lubricant additives, base stock is the main part of a lubricant, and the base stock itself is more important for the protection of the environment [3][4][5].…”

Section: Introductionmentioning

confidence: 99%

Tribological Behavior of Some Long-Chain Dimercaptothiadiazole Derivatives as Multifunctional Lubricant Additives in Vegetable Oil and Investigation of their Tribochemistry Using XANES

et al. 2012

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A series of novel long-chain dimercaptothiadiazole derivatives are prepared and used as antiwear (AW) and extreme pressure (EP) additives in vegetable oil, and their tribological performance is tested by using a four-ball tester. In order to understand the friction process further, X-ray absorption near edge structure spectroscopy is adopted to analyze the chemistry of tribofilms under AW/EP regime, and meanwhile thermal films are also considered for comparison. These derivatives are capable in improving the tribological characteristic of the base stock, and disubstituted derivatives are more effective than other derivatives. Though disubstituted derivatives and disubstituted polysulfur derivatives all fail in improving tribological performance at 0.1 wt%, they are still helpful at other additive concentrations. All these long-chain thiadiazole derivatives, in particular the disubstituted polysulfur ones, are good at improving the EP characteristic of the base colza oil. Thermal films generated from these derivatives are composed of ferrous sulfate and a small amount of adsorbed organic sulfide. During the heating process, these long-chain derivatives easily undergo thermal oxidation to generate high-valent sulfate on the metal surface. Ferrous sulfide is the main component of tribofilms generated by these derivatives, while ferrous sulfate in these films almost vanishes at 1.0 wt%. These long-chain derivatives tend to react with metal surface to generate low-valent sulfide under rubbing conditions. On the other hand, ferrous sulfide is also the main component of EP films generated by monosubstituted derivatives and disubstituted polysulfur derivatives at 1.0 wt%. But the EP films formed by disubstituted derivatives are composed of ferrous sulfide and ferrous sulfate.

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Miscellaneous Additives and Vegetable Oils

Cited by 6 publications

References 1 publication

Laboratory and field performance of biodegradable release agents for hydraulic concrete

Laboratory and field performance of biodegradable release agents for hydraulic concrete

Suitable additives for vegetable oil‐based automotive shock absorber fluids: an overview

Tribological Behavior of Some Long-Chain Dimercaptothiadiazole Derivatives as Multifunctional Lubricant Additives in Vegetable Oil and Investigation of their Tribochemistry Using XANES

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