Mixture of short and long chains

The tribochemical and thermally generated films contained mostly a mixture of short-and long-chain phosphates. The sulfur in tribofilms is always present as sulfide (Canning et al., 1999 Fuller et al., 1997 Yin et al., 1997a). 

At lower temperature, thermally generated film has more similarity to tribofilm. The thermal films, as in the case of the tribofilms, contain mostly a mixture of short-and long-chain polyphosphates. The chemical states of phosphorus and sulfur in each neutral and basic pair were very comparable. The aryl phosphate films contain long-chain polyphosphate throughout the film, whereas the alkyl phosphate films are composed of long-chain polyphosphates in the bulk. Also, the aryl polyphosphate films contain more unchanged ZDDP. 

Thermal film in oil solution Mixture of short and long chain polyphosphates. Sulfur is absent at 200°C present as sulfate at low temp. Mixture of polyphosphates. Above 200°C, sulfur is absent in the film present as sulfate at low temp. Mixture of polyphosphates. Above 200°C, sulfur is absent in the film present as sulfate at low temp. 

The tribofilm composition On the basis of Table 4.1, what analytical surface techniques were used to evaluate the tribofilm composition after ZDDP degradation The tribofilm conditions include the following (a) the tribofilm consists of Zn, P, S, O and Fe and (b) the tribofilm contains mostly of a mixture of short-and long-chain phosphates and sulfur is present as zinc sulfide. What analytical technique has the ability to identify elements and their chemical state, e.g., Fe° or Fe2+, in case (a), and compounds in case (b) More about analytical techniques for evaluation of the metal surfaces can be found in chapter 4.3. 

DAOUD LECLERC Adsorption from a Mixture of Short and Long Chains 25... 

In this paper a methodology is presented to distinguish between two different types of phase behaviour, which occur in binary mixtures of short and long-chain alkanes or polymers. Extensions of the methodology to the more general case of multi component mixtures can find applications in case studies involving solvent selection and mixture... 

In the next section we will discuss how this criterion is used to distinguish between type I and type V phase behaviour in binary mixtures of short and long-chain n-alkanes. 

Synthetic phospholipids are commercially available and they contain polar heads occurring in nature and and the same type of fatty acid in both, 9 -l and sn-2 sites. The acyl chains may be mainly myristoyl (C14 0), palmitoyl (C16 0), olcoyl (C16 l) or stearoyl (C18 0) residues. The physicochemical characteristics of the lipidic bilayers that are prepared from synthetic phospholipids are well defined. The lipid composition influences many physical properties of model membranes and it has been shown that single synthetic lipids or mixtures of short and long fatty acid chains can produce stable lipidic bilayers and liposomes. 

As their name implies, chlorinated paraffins are chlorinated derivatives of paraffinic hydrocarbons. They are referred to in this review as polychlorinated alkanes (PCAs) because they are produced by chlorination of n-alkane feedstocks. Commercial PCA mixtures fall into different categories C10-C13 (short), C 4-C17 (medium) and C2o-C30 (long). These mixtures are further subcategorized into their weight content of chlorine 40-50%, 50-60%, and 60-70% [1,2]. Knowledge of the environmental chemistry of PCAs is needed because the physical properties of short and medium chain mixtures are similar to those of the... 

Chlorinated paraffins are very complex mixtures and are often divided into several groups depending on the chain, length of the starting material and the amount of chlorine in the final product. Three major groups are short-, medium- and long-chained chlorinated paraffins (SCCPs, MCCPs and LCCPs). 

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