Thermal and rheological properties of organogels formed by sugarcane or candelilla wax in soybean oil

Sugarcane wax (SCW) was used to produce organogels and their properties were compared to candelilla wax (CLW) organogels a well known material for this purpose at concentrations of 1 to 4% (w/w). An empirical phase diagram showed that both waxes can form organogels with soybean oil as immobilized phase, SCW organogels were formed at higher concentration and at lower temperatures. The thermal behavior for SCW and CLW was similar, especially during crystallization (T-Onset and T-Peak of 42 degrees C and 41 degrees C respectively) differing only on enthalpy (1.957 and 4.829 J/g respectively), meaning that SCW organogels need less energy to form a network; the melting behavior showed that SCW organogels also need less energy to melt and that both materials presented two melting peaks one of the break of the network and melting of waxes. Rheological behavior presented similar behavior, but with higher values of complex modulus for CLW organogels. In the same way CLW gels showed larger mechanical resistance on compression/extrusion. Micrographs of organogels showed a more organized network present on CLW organogel than SCW organogels that showed larger crystals comparing to CLW organogels. The difference on the microstructure observed explains the difference on the mechanical behavior of organogels formed with both materials. (c) 2012 Elsevier Ltd. All rights reserved.