posted on 2024-02-22, 08:03authored byAdebayo
Isaac Olosho, Md Shafi Alam, Kiran Sukumaran Nair, Ashootosh V. Ambade, Folahan Amoo Adekola
Current attempts to replace fossil-derived
materials
with vegetable
oils for polymer production mainly rely on edible oils. This approach
raises sustainability concerns due to potential food security risks.
This report introduces the first in-depth examination of Thevetia peruviana oil (TPO) epoxidation, an easily
accessible nonedible vegetable oil, utilizing diverse acidic ion-exchange
resins as catalysts. It is followed by the development of vitrimers
based on epoxidized oil (ETPO) with various dicarboxylic acid hardeners.
Amberlite IRC120H emerged as the most effective catalyst for the epoxidation
of the oil, allowing for repeated catalyst reusability for up to five
cycles. An impressive relative oxirane conversion of 98.9% was achieved
after optimization. DSC analysis revealed that among the diacids,
2,2′-dithiodibenzoic acid (DTBZ) has the lowest activation
energy with ETPO. Additionally, the ETPO–DTBZ-based thermosets
displayed exceptional solvent resistance and thermal stability, indicative
of a high degree of cross-linked networks within the system. Mechanical
analyses revealed that all aliphatic hardeners resulted in soft materials,
while DTBZ resulted in thermosets with tensile stress and modulus
of 15 and 843 MPa, respectively. Consequently, DTBZ–ETPO thermosets
were successfully recycled, repaired, and reshaped with minimal changes
in the mechanical properties. The shape memory of the thermosets was
also established.