Tung Oil-Based Unsaturated Co-ester Macromonomer for Thermosetting Polymers: Synergetic Synthesis and Copolymerization with Styrene

Abstract

A novel unsaturated co-ester (co-UE) macromonomer containing both maleates and acrylates was synthesized from tung oil (TO) and its chemical structure was characterized by FT-IR, 1H NMR, 13C NMR, and gel permeation chromatography (GPC). The monomer was synthesized via a new synergetic modification of TO, by introducing maleic groups first and acrylic groups subsequently onto TO molecules. The influence of experimental factors on thermomechanical properties of the cured bioresins was evaluated to better understand structure–property relationships of the biomaterials and optimize experimental conditions. The obtained TO-based co-UE monomer possessed a highly polymerizable CC functionality, consequently resulting in rigid bioplastics with high cross-link densities (νe) and excellent mechanical properties. For instance, the bioplastic prepared under the optimal synthesis conditions demonstrated a νe of 4.03 × 103 mol/m3, storage modulus at 25 °C of 2.40 GPa, and glass transition temperature (T g) of 127 °C, as well as tensile strength and modulus at 36.3 MPa and 1.70 GPa, respectively. A new theory for determining optimal comonomer concentration was further developed according to the copolymerization equation. The proposed theory accurately predicted the best styrene dosage for the co-UE monomer. At last, the hydroxyethyl acrylate (HEA)-modified TO-based resin was compared with the unmodified one in thermomechanical properties, thermal stability, microstructural morphologies, and curing behaviors. The new co-UE bioresin showed higher CC functionality and cross-link density, superior properties including T g and thermal stability, and similar curing behaviors. The developed eco-friendly rigid biomaterials provide potential application in structural plastics such as sheet molding compounds.

Emulsion Polymerization of Tung Oil-Based Latexes with Asolectin as a Biorenewable Surfactant

“…Vegetable oil-based resins recently developed include polyester amides [7], and cyanate esters [8]. Due to their abundance, low cost, readily availability, and renewable nature, vegetable oils have been used for the preparation of films, coatings, and thermosetting resins with interesting thermo-mechanical properties [9,10].…”

“…With over 80% of its fatty acid chains bearing a conjugated triene, tung oil can react with vinyl co-monomers via cationic, thermal, or free radical polymerizations without the need of any structural modification of the triglyceride [9][10][11]. The resulting materials from the polymerization of tung oil consist of highly crosslinked thermosets.…”

Effect of Microwave Cure on the Thermo-Mechanical Properties of Tung Oil-Based/Carbon Nanotube Composites

“…Indeed, the carbon-carbon double bonds in tung oil can readily react with vinyl co-monomers, such as DVB, ST, and dicyclopentadiene, via cationic, thermal, or free radical polymerizations, without the need for structural modifications. It has been shown that these reactions result in highly crosslinked polymer networks [12][13][14][15]. Likewise, tung oil has been used as a key component in cationic bio-based thermosets by crosslinking it with limonene and myrcene [16].…”

Renewable epoxidized cardanol‐based acrylate as a reactive diluent for UV‐curable resins

“…The peaks at 1.4 to 2.9 ppm represented the methylene protons of the alkyl chains. The peak at around 0.9 ppm corresponded to the terminal methyl protons of the alkyl chains . After cardanol was modified by acryloyl chloride, the acrylate proton peaks of CH 2 ═CH― appeared at 5.91, 6.31, and 6.53 ppm in Figure B .…”

“…The peak at around 0.9 ppm corresponded to the terminal methyl protons of the alkyl chains. 36 After cardanol was modified by acryloyl chloride, the acrylate proton peaks of CH 2 ═CHappeared at 5.91, 6.31, and 6.53 ppm in Figure 2B. 22 Compared to the spectra of cardanol Figure 2A and CA Figure 2B, the final product was confirmed by the appearance of the methylene protons of the epoxy groups at 2.9 to 3.1 ppm and the disappearance of proton peaks at 5.46 ppm.…”