In response to the bovine spongiform encephalopathy (BSE) outbreak in the last decade, the US, Canada and several other countries implemented an enhanced feed ban that eliminates specified risk material (SRM) from all animal feed, pet foods and fertilizer applications. The environmental risks and severe loss of profitability by the rendering industry associated with landfilling of several million tons of SRM demand immediate and economically viable solutions of converting such materials into value added applications. In this research, SRM was hydrolyzed, the protein hydrolyzates were extracted and further modified through chemical crosslinking to develop a novel protein‐based plastics. The plastics developed in this research exhibited promising thermal and solvent resistance, and tensile strength.

The effects of salt, molecular weight and viscosity, and mass ratio on the apparent activation energy of the cross-linking reaction of epoxy resins and protein hydrolysate were studied by nonisothermal differential scanning calorimetry. The Kissinger equation, the model-free isoconversional method, and the autocatalytic model were used to analyze the kinetic data. The presence of salts contributed to an increase in the apparent activation energy. The curing of epoxy resins with lower molecular weight protein hydrolysates was found to have lower activation energy and order of reaction. An increase in the concentration of curing groups resulted in a small increase in the order of reaction. The activation energy of curing bisphenol A diglycidyl ether (DGEBA), with viscosity 500–700 cP, was found to be significantly higher than the curing activation energy of polypropylene glycol diglycidyl ether (PPGDE), which has a viscosity of 50 cP.

The effects of salt, water, and temperature on the cross-linking of peptones with glutaraldehyde were studied. At low reaction temperatures, amine groups from peptones form Schiff bases with carbonyl groups of glutaraldehyde. The resulting CN bond is weak and can be easily broken by heat or dissolution in water. As the reaction temperature is increased, the more stable CN bond is formed. A network with low water solubility and significantly improved thermal stability is produced. The presence of salt (sodium chloride) increases the miscibility of peptones and glutaraldehyde solution but also increases the water solubility of the final product. The presence of water also has a dual effect. Water acts as a medium to disperse peptones into glutaraldehyde and is also a hydrogen source to drive the reaction forward. However, water is a byproduct of the reaction. Its presence suppresses the reaction from the standpoint of thermodynamic equilibrium, and it must therefore be driven off (by heat).

BACKGROUND: As a result of the bovine spongiform encephalopathy (BSE) emergence, certain tissues of cattle are categorized as specified risk material (SRM) and completely banned from their traditional applications as an ingredient in animal feed, pet food, or fertilizer applications. The goal of this study was to investigate the hydrolysis of such hazardous proteinacious biomass and extract a safe proteinacious fraction to produce industrial feedstock for value-added applications.

The primary goal of this study was to determine the effect of two protein denaturants, urea and sodium dodecyl sulfate (SDS), on the apparent activation energy of cross-linking bisphenol A diglycidyl ether (DGEBA) with hydrolysate of waste animal proteins. Nonisothermal differential scanning calorimetry was used to measure the apparent activation energy of the reactions. The use of SDS resulted in a marked reduction in activation energy, comparable to the reduction in activation energy when a catalyst for epoxy rings, triethylamine (TEA), was used. The addition of urea slightly increased the activation energy. The heat of reaction increased in the presence of SDS because more reactive sites were made available for curing. This work demonstrates the use of SDS as a protein denaturant additive was an energetically efficient alternative to higher degrees of protein hydrolysis for subsequent curing of DGEBA.