Effects of the Structure and Composition of Montmorillonite on the Dimerization of Unsaturated Fatty Acids

Abstract

The effects of structure and composition of different montmorillonites on their catalytic performance in the dimerization of unsaturated fatty acids were investigated. The dimerization reaction was performed at 240 °C for 3 h, with montmorillonite as catalyst, and LiCl as the co-catalyst. The results showed that the specific surface areas of the different montmorillonites did not have a major effect on their catalytic performance, but the interlayer spacing and surface acidity of montmorillonite show significant effects on the product yield. After the organic modification through hexadecyl trimethyl ammonium bromide (CTAB) intercalation, the microenvironment of the montmorillonite layer changes. Moreover, the inner and outer surfaces change from being hydrophilic to lipophilic, which improves the dispersibility of montmorillonite in fatty acids. The x Al /x Si molar ratios of the three samples are similar and lie within the range of 0.4306-0.5010, thus the x Al /x Si molar ratio has little effect on the dimerization reaction.

Excellent Properties of Dimer Fatty Acid Esters as Biolubricant Produced by Catalyst‐ and Solvent‐Free Esterification

“…Using the optimized solvent‐ and catalyst‐free reaction conditions we previously established, four species of DE were synthesized as shown in Figure . Compared to conventional acid‐catalyzed process, this approach offers several advantages: 1) eliminates several post‐synthesis steps, that is, neutralization, washing and drying processes, which are required to remove the acidity when homogeneous acid catalyst is employed; 2) excess of alcohol used could be retrieved and reused; and 3) without solvent, the production is safer, greener, and of lower cost.…”

“…Using similar catalyst, Yasa et al. (2017) reported polymerization of 10‐undecenoic acid in addition of deionized water (2.5 wt%) affording mixture of iso‐undecenoic acid (47–51%), dimer acid (30–32%), and higher polymeric acids (17–23%) . Further investigation indicated that chemical modification on montmorillonite which led to the change in interlayer spacing and surface acidity has significantly affected the product yield …”

Characterisation of particulate matter and identification of emission sources in Greater Caracas, Venezuela

“…Other authors have also characterised these Fe-mixtures with analytical techniques (i.e. EDX, XRD, XAFS) and morphology characteristics (Geng et al 2014;Mico et al 2015;Boev et al 2013;Jung et al 2012;Campos et al 2009;Fišák et al 2012;Cvetković et al 2012;Huang et al 2018).…”

Influence of Chemical Composition of Activated Calcium Bentonites and Sodium Bentonites on Palm Oil Bleaching Capacity and Oil Quality

“…Because of its anion exchange properties, activated clay often displays a high affinity for anion contaminants, including short-and long-chain alkyl carboxylates, and allows the intercalation of contaminants in the interlayer space (Celis et al, 2014). Moreover, modified clay can provide suitable reaction space for the dimerisation of unsaturated fatty acids and act as a catalyst, which improves dispersibility for the unsaturated fatty acid molecules to enter the interlayer (Huang et al, 2018). A decrease in the iodine value shows a decrease in unsaturated fatty acids, and it indicates oxidation of palm oil, representing a good quality edible oil which has a positive effect on human health (Table 1).…”