Lauric diethanolamide water extractant

In fact any of this additive which extracts from a polymer into distilled water at 60 °C is hydrolysed fairly completely within a few days. The analytical problem, resolves itself, therefore, into the determination of traces of DBA degradation product in the presence of relatively small concentrations of lauric diethanolamide. A method for the determination of lauric diethanolamide and DBA in the aqueous and alcoholic extraction liquids of the British Plastics Bederation (BPB) test conditions and in liquid paraffin is described next. 

Determination of Lauric Diethanolamide and DEA in the Distilled Water Extractant... 

The results in Table 13.3 confirm that lauric diethanolamide is indeed hydrolysed by contact with distilled water for 10 days at 60 °C. To estimate free DEA, one portion of the extractant was analysed directly by the periodic acid procedure. The other portion of extractant was refluxed with 0.1 N sulfuric acid for 6 hours to hydrolyse... 

As lauric diethanolamide is extensively hydrolysed to DEA by distilled water, (i.e., heating for 10 days at 60 C) it would be expected that even more extensive hydrolysis of the additive might occur under the alkaline conditions prevailing in the case of the 5% w/v sodium carbonate extractant. The results in Table 13.4 show that lauric diethanolamide is almost completely hydrolysed to DEA and fatty acid in aqueous sodium carbonate when heated to 60 °C for 10 days. 

No. Dilution of extraction liquid with distilled watCT CcHiceDtration of lauric diethanolamide in original 200 ml extraction liquid (ppm) Volume of diluted extraction liquid used for determination of lauric diethanolamide (ml) Concentration of ethyl alcohol in diluted extraction liquid during reflux with sulfuric add (% wAf) Concentration of sulfuric add in diluted extraction liquid during reflux (N) Volume of distilled water added to extraction liquid immediately prior to iodine back titration (ml) Recovery of added lauric diethanol-amide (%)... 

DEA is water-soluble and can be determined by applying the periodic acid method to a water extract of the liquid paraffin/cyclohexane mixture. A small amount of DEA was found in the liquid paraffin extractant (less than 20% of the 20 ppm w/v of lauric diethanolamide present in the liquid paraffin before the extraction test, see Table 13.8, some of which was present as an impurity in the original batch of lauric diethanolamide used in this work. 

To determine lauric diethanolamide, a further portion of the cyclohexane solution of liquid paraffin was refluxed with 0.5 N sulfuric acid until complete hydrolysis to DBA had occurred. Under these conditions, a twenty-four hour reflux period was needed to hydrolyse lauric diethanolamide completely. Determination of total DBA in the water extract by the periodic acid method (Table 13.8) showed that the lauric diethanolamide recovery was reasonably near to the theoretical value. 

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