Development of biobased polyurethane‐imides from maleinized cottonseed oil and castor oil

Abstract

An eco‐friendly coating system, which is largely biobased, has been developed from castor and cottonseed oil. Cottonseed oil was functionalized with maleic anhydride by “ene” reaction to give maleinized cottonseed oil (MACSO); the anhydride groups were reacted with isocyanates to yield –NCO terminated polyurethane prepolymer. The prepolymer was further chain extended with hydroxyl groups of castor oil to give polyurethane‐imides (PUIs). The cross‐linked films thus obtained had good mechanical properties, and the imide groups in the backbone improved the corrosion resistance of PUIs as revealed by potentiodynamic polarization study. With increasing content of MACSO, thermal stability, glass transition temperatures (Tg), tensile strength, and corrosion resistance of resulting PUIs significantly increased.

Epoxidized and Maleinized Hemp Oil to Develop Fully Bio-Based Epoxy Resin Based on Anhydride Hardeners

“…On the other hand, it can be observed how in the MHO sample ( Figure 6 b), two peaks appear representing the virgin hemp oil sample, located at 1781 and 1861 cm −1 (peak 4) and related to the symmetrical and antisymmetric vibrations of the carbonyl (C=O) of the anhydride groups observed, respectively. This is due to the maleic anhydride used as a reagent in the maleinization process of virgin hemp oil [ 36 ]. This proposal has been supported by studies where maleinized chia oil, which is chemically very similar to MHO, has been analyzed using NMR [ 37 ].…”

Eco-Friendly Photoreversible Adhesives Derived from Coumarin-Functionalized Epoxy Soybean Oil

“…Vegetable oils are one of the eco-friendly feedstocks extensively used as an alternative starting material for synthesizing a variety of polymeric networks due to their abundance, low toxicity, biodegradability, and low cost. − Moreover, they are highly adaptable and reactive because oils from various sources include numerous functional groups, including double bonds and hydroxyl and ester groups, which are suitable for a variety of chemical processes. , Soybean oil (SBO) is the second most available vegetable oil next to palm oil, with a global production of 62 million tons in 2021–2022, and is used for food and industrial applications. , SBO contains nearly 80% of unsaturated fatty acids such as oleic acid, linolenic acid, and linoleic acid, which are easily converted to epoxy groups in the presence of hydrogen peroxide and acid . Epoxidized soybean oil (ESO) is used as a green plasticizer for various polymers, such as polylactic acid , and polyvinyl chloride , and is also used to synthesize epoxy resins. − Further, ESO can be modified with acrylic acid, allyl alcohol, and hydroxyethyl acrylate to synthesize coatings, foams, and adhesives via an efficient free radical polymerization. ,− Moreover, several hydroxylation processes can convert ESO into polyols to manufacture polyurethane. − However, to date, only a few efforts have been made to synthesize reworkable (healable) polymer networks using ESO .…”