Towards Thermally Reversible Networks Based on Furan-Functionalization of Jatropha Oil

Abstract

A novel biobased monomer for the preparation of thermally reversible networks based on the Diels-Alder reaction was synthesized from jatropha oil. The oil was epoxidized and subsequently reacted with furfurylamine to attach furan groups via an epoxide ring opening reaction. However, furfurylamine also reacted with the ester groups of the triglycerides via aminolysis, thus resulting in short-chain molecules that ultimately yielded brittle thermally reversible polymers upon cross-linking via a Diels-Alder reaction. A full-factorial experimental design was used in finding the optimum conditions to minimize ester aminolysis and to maximize the epoxide ring opening reaction as well as the number of furans attached to the modified oil. The optimum conditions were determined experimentally and were found to be 80 °C, 24 h, 1:1 molar ratio, with 50 mol % of LiBr with respect to the modified oil, resulting in 35% of ester conversion, 99% of epoxide conversion, and an average of 1.32 furans/triglyceride. Ultimately, further optimization by a statistical approach led to an average of 2.19 furans per triglyceride, which eventually yielded a flexible network upon cross-linking via a Diels-Alder reaction instead of the brittle one obtained when the furan-functionalization reaction was not optimized.

Click chemistry for the synthesis of biobased polymers and networks derived from vegetable oils

“…The products showed varying flexibility depending on the chain length, the number of furans attached, and cross-links. 125 Bearing in mind these results, the same authors explored the cross-linking of furan-functionalized jatropha and sunflower oils with aliphatic and aromatic BMIs. The thermal properties were also influenced by the type of oil employed, and sunflower-based polymers showed higher Tg values.…”

Self-Healing, Recyclable, and Degradable Castor Oil-Based Elastomers for Sustainable Soft Robotics

“…Recently, the synthesis of a self-healing CO 2 -based polyurethane urea DA network that heals with an efficiency up to 94% upon heating to 120 °C for 10 min and 60 °C for 24 h was reported . Gandini and co-workers focused on the use of vegetable oils, highlighting the potential use of several types of oils and furan monomers to obtain thermoreversible materials. − Similarly, the group of Francesco Picchioni recently reported materials based on Jatropha oil using the Diels–Alder reaction. , However, none of these two last works mention self-healing properties or any kind of mechanical characterization of the materials. To the best of our knowledge, there is only one work reporting the use of some form of vegetable oil to make self-healing materials based on the Diels–Alder reaction .…”

“…41−46 Similarly, the group of Francesco Picchioni recently reported materials based on Jatropha oil using the Diels−Alder reaction. 47,48 However, none of these two last works mention self-healing properties or any kind of mechanical characterization of the materials. To the best of our knowledge, there is only one work reporting the use of some form of vegetable oil to make self-healing materials based on the Diels−Alder reaction.…”

A review of fatty epoxide ring opening reactions: Chemistry, recent advances, and applications

“…Other acidic catalysts include nonprotic 1‐methyl imidazolium tetrafluoroborate (MIT), an ionic liquid (Biswas et al, 2009), and heterogeneous sulfuric acid‐activated bleaching earth (Dahlke et al, 1995). Lastly, lithium bromide (LiBr) catalyzes aminolysis of epoxides through electrophilic activation of oxiranes by strongly oxophilic Li + cations for subsequent nucleophilic attack by amines (Chakraborti et al, 2004; Yuliati et al, 2020). In the absence of catalyst, negligible product is formed from aminolysis of internal fatty epoxides, even at high (200°C) temperatures (Radojcic et al, 2016).…”