Muhammad Safder | ALES Graduate Seminar

Event details: A graduate exam seminar is a presentation of the student’s final research project for their degree.
This is an ALES PhD Final Exam Seminar by Muhammad Safder. This seminar is open to the general public to attend.
Thesis Topic:  Lipid Extraction and Bionanocomposites Synthesis from Spent Hens

PhD with Drs. Aman Ullah and Feral Temelli

Seminar Abstract:

Spent hen, a poultry industry by-product with little market value and high lipid content, can be used as a new and sustainable biomass source for lipid production. This study focused on environmentally benign extraction methods, i.e., the microwave-assisted and supercritical CO₂ extraction of lipids from the spent hen and conversion of extracted lipid into bionanocomposites.

First, over 95% of the lipids were recovered within 10 min using microwaves. Factors affecting the lipid extraction yield, including extraction time, temperature, and the solvent-to-feed ratio were studied using response surface methodology. To account for the low sample size, parametric bootstrapping was used with a replacement approach. Data in all combinations were bootstrapped 10,000 times, which showed a decrease in standard deviation. The lipids predominantly contained oleic (46%), linoleic (~22%), and palmitic (~23%) acids. The phase transitions and thermal degradation behavior of lipids were determined using differential scanning calorimetry and thermogravimetric analysis, respectively.

Second, lipids were extracted using supercritical carbon dioxide (SC-CO₂) at 50−70 °C, 30−50 MPa, and constant CO₂ flow rate of 1 L/min. The maximum yield of total lipid 37% (w/w) with 92% recovery was obtained at 50 MPa/70 °C. Fatty acid compositional analysis was performed using gas chromatography with flame ionization detector (GC-FID). Helium ion microscopy (HIM) was used to assess the morphological changes before and after extraction. Furthermore, epoxidation of the extracted lipids was conducted with and without the use of a solvent, where the solvent-free epoxidation was completed within 20 min. The reaction progress was monitored by attenuated total reflectance-Fourier transform infrared (ATR-FTIR) and ¹H NMR spectroscopy analysis, which showed the conversion rates of 59.8, 84.2 and 100% at 5, 10, and 20 min, respectively. The findings suggest that an alternative bio-epoxy can be produced using SC-CO₂ extraction and solvent-free epoxidation of extracted lipids.

Third, a monomer was synthesized using the mixture of fatty acids obtained through the hydrolysis of triglycerides extracted from spent hens. The reaction conditions of temperature and time were studied to obtain a high molecular weight biopolymer using bulk polymerization. The bionanocomposites were then prepared with different ratios of nanoclay (0, 3, 5, and 10%) using in situ polymerization. The bionanocomposite films were prepared using compression molding and the effect of nanoparticle addition, in terms of their dispersion and impact on the final material properties, was investigated by different characterization techniques. Results indicated improved thermal stability for nanoreinforced biocomposites. The flammability test showed substantial improvements in the flame retardancy of bionanocomposites compared to the neat biopolymer. These results suggest that high-performance bionanomaterials can be developed from spent hen lipids.

Finally, a novel unsaturated macromonomer containing both saturated and unsaturated fatty acids was synthesized from spent hen lipids. The monomer was synthesized via epoxidation modification of spent hen lipids, followed by grafting nanocellulose groups and acrylic groups subsequently onto spent hen lipid molecules. The bionanocomposites were prepared by in situ addition of modified nanoclay in different proportions. Also, the nanocomposites were synthesized by copolymerization of spent hen lipid monomer and styrene. The obtained spent hen lipid monomer possessed a highly polymerizable C═C functionality, consequently resulting in rigid bioplastics. The synthesized cross-linked biomaterial from spent hen lipids provide a material showing potential for use in structural plastics.

In summary, lipids were extracted from the whole carcass of spent hens with high yields by microwave-assisted and SC-CO₂ extraction and converted to bioepoxy materials. Furthermore, the extracted lipids were converted to bionanocomposites with enhanced thermal stability and flame retardancy properties. Moreover, environmentally friendly technologies such as microwave-assisted extraction and SC-CO₂ extraction not only helped to reduce the lipid extraction time, but also minimized the use of toxic organic solvents. Overall, in addition to several environmental advantages, this research would benefit poultry, packaging, food and plastics industries.