**2.2 Chemical characterization of a paraffin inhibitor additive**

A paraffin inhibitor additive was analyzed by py-GC/MS at a pyrolysis temperature of 600°C. The pyrogram is shown in **Figure 7**.

### **Figure 7.**

*Py-GC/MS of the paraffin inhibitor additive.*

The following products were detected after the pyrolysis of the sample (See **Tables 2–4**):


### **Table 2.**

*Relative composition expressed as area percentage.*


### **Table 3.**

*Relative composition of the methacrylate fraction expressed as area percentage.*


### **Table 4.**

*Relative composition of the acrylate fraction expressed as area percentage.*

*Pyrolysis-GC/MS, A Powerful Analytical Tool for Additives and Polymers Characterization DOI: http://dx.doi.org/10.5772/intechopen.101623*


### **2.3 Chemical characterization of lubricity improvers additives**

Samples were analyzed by py-GC/MS at a pyrolysis temperature of 600°C. The pyrograms are shown in **Figure 8**.

The pyrolysis of the second lubricity improver additive generates a complex mixture of products mainly with saturated and monounsaturated C16 and C18 hydrocarbon chains, they are generally quite branched, and they are presented in the following families of products, always in the form of a mixture of isomers:

• Olefins.

• Alkenyl-succinic anhydrides.

**Figure 8.** *a) Py-GC/MS of lubricity improver additive 1 and b) 2.*

	- Mix of linear mono-olefins C6 to C13.
	- Palmitic and stearic acids.
	- Succinic anhydride.
	- 2-hydroxyethanol acrylate.
	- C4 fraction (butenes)
	- Ethylene glycol.
	- Traces of aromatic fraction (benzene-naphthalene)

The pyrolysis of the second lubricity improver additive produces species similar to that of the previous one, with the only difference in the length of the hydrocarbon chains, which in this case are mostly C14 and C16.

### **2.4 Chemical characterization of viscosity index improvers additives**

Four viscosity index improvers additives were analyzed by Py-GC/MS at a pyrolysis temperature of 600°C. The pyrograms are shown in **Figures 9** and **10**.

**Figure 9.** *Py-GC/MS of two of the viscosity index improvers additives.*

**Figure 10.** *Py-GC/MS of two of the viscosity index improvers additives.*

The obtained chromatograms make it possible to identify the compounds from the pyrolysis of the polymeric fraction:


By normalizing the response of the detected alkyl-methacrylates (**Figure 11**), the comparative results that are shown in **Tables 5** and **6** are obtained.

Traces of methacrylic acid are also detected in all four samples.

Poly(methylmethacrylate) is formed by a polymerization reaction of methyl methacrylate.

### **Figure 11.**

*Poly(methyl methacrylate) formation.*


### **Table 5.**

*Relative composition expressed as area percentage.*


### **Table 6.**

*Relative composition expressed as area percentage.*

The polymer fraction of the four samples can be described as mixtures of polymethyl-methacrylate (PMMA) with poly-alkyl-methacrylates (PAMAs) in an approximate ratio 1:1, the latter mainly with C12, C14 and C16 radicals.

All samples show signals corresponding to hydrocarbon bases of mineral origin in the boiling point range between 1-dodecene and 1-octadecene.

Obtained data are based on:

Normalization of areas of the methacrylate fraction, for the distribution of the alkyl groups.

Signal of the mineral base by contribution of areas to the total ionic current diagram. These data are not quantitative, so they can only be interpreted in comparative terms.
