Narine, Suresh SN
Fractionation and Evaluation of Carapa guianensis Seed Oil
The seed oil of Carapa guianensis, known as Crabwood oil (CWO) and its fractionation was studied, focussing on chemical composition and physicochemical functionality. Compounds never reported before in CWO were identified, including limonoids such as Trichillin, ketostearic and hydroxyoleic acids. Yield of olein and stearin fractions correlated strongly with solvent polarity. Important bioactives were partitioned as a function of solvent polarity in the olein vs. stearin fractions. For example, up to 35% more of Gedunin were present in the liquid fractions. Solid fat content, crystallization and melting temperature and microstructure were significantly affected by fractionation and shown to be strongly correlated with solvent polarity. Fractionation was demonstrated to be a powerful tool to extend the physical functionality of CWO and concentrate its bioactives.
Author Keywords: Carapa guianensis, Chemical characteristics, Crabwood Oil, Dry and Solvent fractionation, Fractionation, Physical characteristics
Molecular Architectures for Improved Biomaterials Derived from Vegetable Oils – Application to Energy Storage and Lubricants
The replacement of petroleum with renewable feedstock for energy and materials has become a priority because of concerns over the environment and finite nature of petroleum. The structures of the available natural biomass feedstocks fall short in delivering key functionality required in materials such as lubricants and phase change energy storage materials (PCMs). The approach taken in this thesis was to combine select functional groups with vegetable oil derivatives to create novel PCMs and lubricantswhich deliver desired functionality. One series of diester PCMs were prepared with terephthalic acid and fatty alcohols to address known shortcomings of esters. The second class of PCMs are sulfones prepared from oxidation of fatty sulfides to improve thermal energy storage. Overall, the new PCMs presented narrow phase change temperature ranges, high transition temperature (between 67 to 110℃), high transition enthalpy (210 to 266J/g), minimal supercooling and congruent phase transitions unaffected by cooling rates. They also demonstrated higher thermal degradation stability with onset of degradation from 290 to 310℃. The series of lubricants studied consists of sulfide and sulfonyl functional groups attached to the unsaturation sites of oleyl oleate as pendant groups to improve the thermal and flow properties. The new lubricants present subzero crystallization temperatures, very low crystallization enthalpy and dynamic viscosity as high as 180mPas.
Furthermore, they also presented high onset of degradation (up to 322℃) and oxidation (up to 298℃). The PCMs and lubricants of the present thesis demonstrate that select functional groups can be used with common structural elements of vegetable oil such as fatty acids, ester groups and unsaturation sites to make a variety of molecular structures capable of delivering desired properties
Author Keywords: Crystal Structure, Lubricant, Phase Change Material, Renewable, Structure-Property Relationships, Vegetable Oil