Physical Properties of Organogels Made of Rice Bran Wax and Vegetable Oils

This chapter presents the physical properties of organogel made of Rice Bran Wax (RBX) and vegetable oils, examined with thermal, structural, and optical methods. The physical properties of organogels formed by RBX and liquid oils in comparison with other typical plant waxes of Candellila Wax ( CLX) and Carnauba Wax (CRX) can be summarized as follows: (a) the rate of formation of organogels was highest for RBX gels, as determined by visual observation and viscosity-temperature relationships, (b) the hardness assessed by the penetration depth measurement was highest for RBX gels, (c) thermal stability expressed as the T_m of wax crystals in organogels was highest for RBX gels. These properties may be ascribed to the high crystallinity of RBX crystals having the highest δH_m and δS_m, whose values are similar to those of the PPP β form. As PPP crystals are tightly packed in the T_// subcell, it is reasonable to assume that the RBX crystals are also tightly packed in the O_⊥ subcell structures. The differences in the subcell structure may be responsible for the molecular differences between RBX and PPP structures. Furthermore, the crystal morphology of the needle-shaped RBX crystals in organogels may indicate a greater ability to entrap the liquid oils to form organogels. Crystallization kinetics and physical properties of organogels prepared by RBX and different. Furthermore, the crystal morphology of the needle-shaped RBX crystals in organogels may indicate a greater ability to entrap the liquid oils to form organogels.