Synthesis and Properties of Tung Oil-Based Unsaturated Co-Ester Resins Bearing Steric Hindrance

Abstract

New tung oil (TO)-based, unsaturated, co-ester (Co-UE) macromonomers bearing steric hindrance were synthesized by modifying a TO-based maleate (TOPERMA) monomer with an anhydride structure with hydroxyethyl methacrylate (HEMA) and methallyl alcohol (MAA), respectively. The obtained Co-UE monomers (TOPERMA-HEMA and TOPERMA-MAA) were then characterized by 1H NMR and gel permeation chromatography (GPC). For comparison, hydroxyethyl acrylate (HEA)-modified TOPERMA (TOPERMA-HEA) was also synthesized and characterized. Subsequently, the obtained Co-UEs were thermally cured with styrene, and the ultimate properties of the resulting materials were studied. It was found that by introducing the structure of steric hindrance into the TO-based Co-UE monomer, the tensile strength and Young’s modulus of the resulting materials were improved. Furthermore, by reducing the length of the flexible chain in the Co-UE monomer, the tensile strength, Young’s modulus, and glass transition temperature (Tg) of the resultant materials were also improved. The TOPERMA-MAA resin gave the best performance in these TO-based Co-UE resins, which showed a tensile strength of 32.2 MPa, Young’s modulus of 2.38 GPa, and Tg of 130.3 °C. The developed ecofriendly materials show promise in structural plastic applications.

Hydrophobic Shape-Memory Biocomposites from Tung-Oil-Based Bioresin and Onion-Skin-Derived Nanocellulose Networks

“…It can be seen from Figure 5a that in the glassy state, the resins with the higher FMA contents (T1F6 and T1F9) have a higher storage modulus than that with the lower FMA content (T1F3). Higher FMA contents lead to increased steric bulk due to the DA adducts, yielding stiffer resins [13,53]. A sharp decrease in the storage modulus was observed in the range −10 • C to 20 • C for T1F3 and −10 • C to 40 • C for T1F6 and T1F9, due to the increase in segmental mobility of the long flexible hydrocarbon chains from the acrylated TO moiety.…”

Bio-Based Polymers for Engineered Green Materials

“…Several interesting bio-based polymers from other resources and processes are also presented. Polyesters and NIPU were synthesized using vegetal oils, offering products with enhanced mechanical properties and high thermal stability, respectively [29,30]. Latex was exposed to photodegradation catalyzed by TiO 2 to obtain easy-to-manage low molecular weight rubber [31].…”

The Hyperbranched Polyester Reinforced Unsaturated Polyester Resin

“…It has been proven that the effect of modifying additives on the properties of polymer composites is determined by many factors, such as the type of reactive diluent [ 23 ], synthesis route and raw materials [ 24 , 25 ], the application field of composites [ 26 ], etc. As mentioned above, hyperbranched polyester can strengthen and toughen the resin by introducing specific functional groups due to its special structural characteristics.…”