Tung oil (TO)/ultraviolet (UV) photo-composite curing material possesses the characteristics of low curing temperature, low material shrinkage and low environmental pollution. Accordingly, this material must be developed and utilized with the conjugated double bonds contained in the long chain of the main structure (α-tung acid) molecules in the refined TO. The aforementioned material can be chemically modified using a variety of chemical methods to develop a new TO-based UV photocurable material due to its unique chemical properties. This work reviews the research progress of TO/UV photo-composite curing materials in recent years. Firstly, the chemical structure and application of TO and UV Photocatalysis Technology were briefly introduced. Secondly, the research status of novel TO/UV photo-composite curing materials developed by the Diels-Alder reaction was discussed. The method and curing effect of the UV curing system constructed by other chemically modified TO were also discussed. Thereafter, the application of TO in industrial production is introduced from four directions: the application of TO in biodiesel, the application in synthetic resin, the application in self-healing coating and microcapsules and other applications. Finally, the research and application prospects of TO/UV photo-composite curing materials were presented.
Using tung oil as the raw material, a new bio-based prepolymer was successfully synthesized by reacting with acrylic-modified rosin (β-acryloyl nutrient ethyl) ester (ARA)/acrylic-2-hydroxyethyl ester (HEA) followed by the use of the above composite material as the matrix and then reacting with the active diluent (2-HEMA, TPGDA) and the photoinitiator TPO and Irgacure1173 to successfully synthesize a new type of bio-based prepolymer-acrylate-epoxy tung oil polypolymer (AETP). The tung oil monomer before and after the epoxy formation was compared by proton NMR spectroscopy, and the chemical structure of AETP was analyzed by Fourier transform spectroscopy. Tung oil has an acid value of 1.5 mg KOH per g, an epoxy value of 5.38%, an iodine value of 11.28 g/100 g, and a refractive index of n25 = 1.475. Composite-based 3D printing resins (like AETP) were cured using digital light treatment, while some samples were also post-treated via ultraviolet (UV) light treatment. The AETP-based 3D printing resin has excellent thermal and mechanical properties, and the viscosity of its system is 313 mPa s; exposure time 4.5 s; the tensile strength, flexural strength and flexural modulus were 62 MPA, 63.84 MPa and 916.708 MPa, respectively; Shore hardness was 80 HD and shrinkage was 4.00%. The good performance of the AETP-based 3D printing resin is attributed to the rigidity of their tightly crosslinked structure. This study pioneered a method for producing photoactive acrylates (e.g., tung oil-based acrylate oligomer resins) from renewable, low-cost biomass for light-curing 3D printing.
Tung oil is an important dry grease. In order to overcome the deficiencies of traditional processes in oil production, the preparation of tung oil was carried out by the butane-subcritical method. A response surface optimization experiment was carried out based on Design-Expert software, and the best process parameters were obtained. The extraction temperature was 42.98 °C, the extraction time was 43.77 min, the particle size of the raw material was 38.88 mesh, and the oil yield of tung oil under this condition reached 67.437%. The fatty acid composition of tung oil was analyzed by Gas Chromatography-Mass Spectrometry (GC-MS): the content of α-oleostearic acid was 74.99%, linoleic acid content was 8.83%, oleic acid content was 7.42%, palmitic acid content was 2.02%, and stearic acid content was 4.35%. Through the analysis of the oil sample obtained, five indicators showed that the process of obtaining oil products met the requirements of the national standard. By simulating the subcritical n-butane/tung oil dissolution equilibrium model, the miscible dynamic equilibrium of tung oil in subcritical n-butane was studied at temperatures in the range of 35–50 °C and an equilibrium time of 40 min, and the kinetic equations of oil extraction at different temperatures were obtained, with a coefficient of determination (R2) greater than 0.99. The oil extraction rate was up to 67.12 ± 0.05% under optimal extraction conditions through the optimization of univariate and response surface experimental design. Using 1stOpt data processing software, the data of tung oil extraction rate at different times were fitted, and it was found that the Patricelli model accurately elucidated the kinetic process of tung oil extraction through subcritical n-butane, with R2 greater than 0.99.
1 October 2019 in IOP Conference Series: Earth and Environmental Science
Litsea cubeba is a rich woody oil plant resource in China. The economic value of Litsea cubeba oil is high. In order to improve the resource utilization rate of Litsea cubeba, this study used microwave-assisted water method to extract Litsea cubeba kernel oil from the seeds of Litsea cubeba. The optimum process conditions were as follows: microwave time 60 min, extraction temperature 80.18 °C, liquid-to-liquid ratio 11.46:1, microwave power 587.44 W. Under this optimized condition, the extraction rate of Litsea cubeba kernel oil was 37.54%. It can be seen that the microwave assisted water generation method for extracting Litsea cubeba nucleolus oil is reliable and has certain utilization value.
1 May 2018 in IOP Conference Series: Earth and Environmental Science
Tung oil, as a kind of drying oil, with the influence of water, acid, alkali, or light, is easy to have variation. This research adopts the active carbon decoloring refining process in tung oil refining, and response surface experiment process is adopted to optimize the process. And finally I obtain the best process condition: temperature 80.17 °C, decoloring time 90.71 min, decoloring dosage 3.49%, and the decolorization rate was 92.48% under the condition. Tung oil were analyzed by gc instrument, and found that the main ingredients is cis, trans, trans - 9,11,13-18 carbon triene acid, with content as high as 70.31%, which determines the physical and chemical properties of tung oil. Through the functional groups absorption peak of tung oil (before and after decolorization) by – IR, founding that the technology can guarantee the quality of tung oil very well.