Asolectin from soybeans as a natural compatibilizer for cellulose‐reinforced biocomposites from tung oil

Abstract

The free radical copolymerization of tung oil, divinylbenzene, and n-butyl methacrylate results in bio-based thermosetting polymers with tunable properties. Biocomposites have been obtained by the reinforcement of such bio-based resins with a-cellulose. Asolectin from soybeans consists of a mixture of natural, polyunsaturated phospholipids. Because of its long, unsaturated fatty acid chains, and the presence of phosphate and ammonium groups, asolectin from soybeans is a good candidate for acting as a natural compatibilizer between the hydrophobic matrix and the hydrophilic reinforcement. In the current work, we investigate the changes in properties resulting from the addition of asolectin to a tung oil-based polymer reinforced with a-cellulose. An evaluation of the curekinetics of the tung oil-based resin has been conducted by dielectric analysis (DEA), and the final biocomposites have been thoroughly characterized by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), Soxhlet extraction, and scanning electron microscopy (SEM).

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

“…Whenever vegetable oil-based thermosetting resins are reinforced with materials exhibiting a polar surface, there is an intrinsic incompatibility between the hydrophobic resin and the hydrophilic reinforcement, which can be overcome by the addition of compatibilizers to the resin formulation [3,12]. Very recently, the successful use of asolectin as a natural compatibilizer for cellulose-reinforced tung oil-based composites has been reported [13].…”

“…Indeed, the mixture contains approximately 25% of phosphatidylcholine, 25% of cephalin, and 25% of phosphatidylinositol ( Figure 1), with the remainder consisting of small amounts of other phospholipids from soybeans [15]. Due to its amphiphilic nature, asolectin interacts with non-polar resin components through its fatty acid chains and with the hydrophilic reinforcement through the phosphate and ammonium groups [13]. The polyunsaturated fatty acids in asolectin enable the phospholipid to be free radically crosslinked to other reactive and compatible olefins upon cure [13].…”

“…Due to its amphiphilic nature, asolectin interacts with non-polar resin components through its fatty acid chains and with the hydrophilic reinforcement through the phosphate and ammonium groups [13]. The polyunsaturated fatty acids in asolectin enable the phospholipid to be free radically crosslinked to other reactive and compatible olefins upon cure [13]. Due to obvious similarities in the structures of phospholipids and triglycerides, a copolymer of tung oil and asolectin is readily formed in the presence of a free radical initiator [13].…”

“…The polyunsaturated fatty acids in asolectin enable the phospholipid to be free radically crosslinked to other reactive and compatible olefins upon cure [13]. Due to obvious similarities in the structures of phospholipids and triglycerides, a copolymer of tung oil and asolectin is readily formed in the presence of a free radical initiator [13]. When cellulose/tung oil-based composites are prepared with asolectin, improved thermo-mechanical properties are obtained in comparison to composites prepared without asolectin [13].…”

“…Due to obvious similarities in the structures of phospholipids and triglycerides, a copolymer of tung oil and asolectin is readily formed in the presence of a free radical initiator [13]. When cellulose/tung oil-based composites are prepared with asolectin, improved thermo-mechanical properties are obtained in comparison to composites prepared without asolectin [13]. The preparation of latexes and emulsions containing bio-based polymers allow for smooth film depositions leading to bio-based coatings [15,16].…”