Effect Of Phosphate Esters Research Articles

Tribological behaviour of three phosphate esters containing the benzotriazole group as additives in rapeseed oil

Since the 1970s more attention has been paid to biodegradable lubricants as a way of reducing the pollution caused by lubricants with a mineral oil base. This concern has promoted the use of vegetable oils as alternative base oils. This paper reports on a study of the effect of phosphate esters containing the benzotriazole group as additives in rapeseed oil (RSO), tests being carried out using a standard four-ball tester. The results show that these additives produce good antiwear performance and load-carrying capacity compared with RSO alone. Surface analysis of the worn halls was carried out using X-ray photoelectron spectroscopy. The tribological mechanism is discussed on the basis of the experimental results.

Effect of phosphate esters on PVC flammability from a multi‐test viewpoint

AbstractMany tests have been developed to provide relative flame/smoke data. In spite of the proliferation of such tests and test equipment, many chemical and polymer producers, as well as fabricators, use only one technique to evaluate the flame/smoke properties of a polymer system. This paper demonstrates the importance of multi‐method testing to rate the efect of phosphate esters and various fillers on PVC flammability and smoke generation.

Effect of phosphate esters, nucleotides and nucleosides on 5'-nucleotidase of cultured mouse macrophages.

Mouse peritoneal macrophages elicited by intraperitoneal injection of sodium caseinate exhibit low levels of ecto-5'-nucleotidase (E. C. 3.1.3.5) activity in contrast to macrophages obtained by peritoneal lavage. When elicited cells were cultured under standard conditions in the presence of serum, a 2.5-fold increase in 5'-nucleotidase activity was observed over a period of 48 hours. Addition of adenosine monophosphate to the culture medium led to an augmented (5-fold) increase in the specific activity (per unit cell protein) as well as an absolute increase (per culture plate) of 5'-nucleotidase. Other adenosine-containing compounds also had stimulatory effects. The levels of this enzyme thus appear to be regulated by the extracellular levels of adenosine nucleotides. The product of the enzymatic reaction--adenosine--when added to the medium exhibited a toxic effect on these cells--as did adenosine monophosphate. However, the former substance did not augment the increase in enzyme activity during culture. The toxic effect could be suppressed when the cells were cultured in the presence of uridine 5'-monophosphate. The latter substance also depressed the stimulation of enzyme activity due to AMP.

Further studies with additives: Effects of phosphate esters and ammonium salts on the activity of leaf‐applied herbicides

AbstractThe phytotoxicity of glyphosate applied to the leaves of dwarf bean (Phaseolus vulgaris L.) and several woody species was enhanced by mixed butyl acid phosphates (BAP, a technical mixture of dibutyl hydrogen and butyl dihydrogen phosphates) or ammonium sulphate. Tributyl phosphate, or the mixed sodium salts of BAP, similarly increased the activity of aminotriazole. This type of effect did not occur with mixtures of this herbicide and inorganic ammonium salts or the ammonium salts of BAP. Neither phosphate esters nor ammonium salts enhanced the activity of paraquat. Ammonium BAP was more effective than sodium BAP as an activator for leaf‐applied picloram or MCPA salts. While phosphate esters and ammonium salts probably have separate modes of action they have similar effects in mixture with many water‐soluble herbicides and for many purposes may be regarded as alternative activators. Ammonium salts, particularly ammonium sulphate, have obvious advantages because of their cheapness and low mammalian toxicity.