TRIGLYCERIDE SYSTEMS FORMING MOLECULAR-COMPOUNDS

Binary triglyceride systems containing palmitic, stearic, and oleic acids have been examined by X-ray powder diffraction and differential scanning calorimetry. Molecular 1:1-compounds occur in two kinds of systems: 2-oleoyl-disaturated/1-oleoyl-disaturated and 2-oleoyl-disaturated/2-saturated-dioleoyl. The general packing principles in the solid state are proposed for the systems and according to this different chain packings exist in different layers within the same crystal form. Diffraction pattern versus temperature shows an enhanced polymorphic transition to the 1:1-compound. In diffraction pattern versus time measurements, above the melting point of the alpha-form, the crystallization process goes directly to the beta-form, but, according to experimental results, the beta'-form exists as a transition state.