Nonisothermal Curing of DGEBA with Bloodmeal-based Proteins

Abstract

Differential scanning calorimetry (DSC) was used to study the curing reaction of bisphenol A diglycidyl ether (DGEBA) and Novatein thermoplastic protein (NTP). NTP is made from bloodmeal and is ∼60% protein. Activation energy (E α ), pre-exponential factor (ln A o ) and order of reaction (m + n) were calculated using the Kissinger, model-free isoconversional and autocatalytic models. Curing kinetics were almost independent of concentration and the addition of plasticizers and protein denaturants to bloodmeal caused a decrease in E α of ∼50%. Increasing protein denaturants had little effect on the reaction; however, inclusion of salt proved detrimental. At NTP's maximum processing temperature (∼450 K), using an equal molar ratio of epoxy groups to reactive amino acids, 75% conversion can be reached in 3 min based on the modeling done here.

The relationship between morphology development and mechanical properties in thermoplastic protein blends

“…However, the epoxy will only react with protein at high temperature [21] whilst MA will develop acid-base or covalent interaction with the protein, provided the anhydride is hydrolysed and ring opens. The chemical functionality present on the PE in the blend is an integral part of the morphology development, and the influence that morphology has on mechanical properties.…”

“…At both low and high LOT contents (6 and 20 pph Novatein ) polyethylene was encasing regions of Novatein suggesting a co-continuous network (Figure 2b,b′). [21,33] However, the epoxy group could ring open, providing a more hydrophilic group that could assist in compatibilization. [32] Interaction at the interface improved over CTN blends, although a chemical reaction between the epoxy functionality and Novatein was not confirmed.…”

“…This would imply that the method of morphology development is dominated by droplet-droplet coalescence. The low reactivity of the epoxy functionality towards Novatein at the processing temperatures used in this study [21,22,33] would be a contributing factor as to why CTN and LOT behave in a similar fashion, where there was a distinct lack of interaction between the two phases. The low reactivity of the epoxy functionality towards Novatein at the processing temperatures used in this study [21,22,33] would be a contributing factor as to why CTN and LOT behave in a similar fashion, where there was a distinct lack of interaction between the two phases.…”

“…[20][21][22] Other commercially available PE's were chosen to contain glycidyl methacrylate (GMA) or carboxylic acid partially neutralised with zinc oxide to manipulate compatibility, interfacial adhesion and ultimately the morphology. Unmodified LDPE was used as a control, whilst the inclusion of PE-g-MA was also used as a comparison of a ternary blend.…”

Structural changes and energy absorption mechanisms during fracture of thermoplastic protein blends using synchrotron FTIR

“…3b), as shown through solvent extraction of the Novatein phase [6]. The modification of LDPE to include reactive GMA functionalities (LOT blends) did not improve compatibility due to the low reactivity of epoxides and functional amino acids at the chosen processing temperature [27] (Fig. 3c).…”