Grauzeliene Sigita, Navaruckiene Aukse, Skliutas Edvinas, Malinauskas Mangirdas, Serra Angels, Ostrauskaite Jolita
Department of Polymer Chemistry and Technology, Kaunas University of Technology, Radvilenu Rd. 19, LT-50254 Kaunas, Lithuania.
Laser Research Center, Faculty of Physics, Vilnius University, Sauletekis Ave. 10, LT-10223 Vilnius, Lithuania.
Polymers (Basel). 2021 Mar 12;13(6):872. doi: 10.3390/polym13060872.
The use of renewable sources for optical 3D printing instead of petroleum-based materials is increasingly growing. Combinations of photo- and thermal polymerization in dual curing processes can enhance the thermal and mechanical properties of the synthesized thermosets. Consequently, thiol-ene/thiol-epoxy polymers were obtained by combining UV and thermal curing of acrylated epoxidized soybean oil and epoxidized linseed oil with thiols, benzene-1,3-dithiol and pentaerythritol tetra(3-mercaptopropionate). Thiol-epoxy reaction was studied by calorimetry. The changes of rheological properties were examined during UV, thermal and dual curing to select the most suitable formulations for laser direct writing (LDW). The obtained polymers were characterized by dynamic-mechanical thermal analysis, thermogravimetry, and mechanical testing. The selected dual curable mixture was tested in LDW 3D lithography for validating its potential in optical micro- and nano-additive manufacturing. The obtained results demonstrated the suitability of epoxidized linseed oil as a biobased alternative to bisphenol A diglycidyl ether in thiol-epoxy thermal curing reactions. Dual cured thermosets showed higher rigidity, tensile strength, and Young's modulus values compared with UV-cured thiol-ene polymers and the highest thermal stability from all prepared polymers. LDW results proved their suitability for high resolution 3D printing-individual features reaching an unprecedented 100 nm for plant-based materials. Finally, the biobased resin was tested for thermal post-treatment and 50% feature downscaling was achieved.
使用可再生资源而非石油基材料进行光学3D打印的情况日益增多。双固化过程中光聚合和热聚合的结合可以提高合成热固性材料的热性能和机械性能。因此，通过将丙烯酸化环氧大豆油和环氧亚麻籽油与硫醇、苯-1,3-二硫醇和季戊四醇四(3-巯基丙酸酯)进行紫外光固化和热固化相结合，得到了硫醇-烯/硫醇-环氧聚合物。通过量热法研究了硫醇-环氧反应。在紫外光固化、热固化和双固化过程中检测流变性能的变化，以选择最适合激光直写(LDW)的配方。通过动态热机械分析、热重分析和力学测试对所得聚合物进行了表征。对所选的双固化混合物进行了LDW 3D光刻测试，以验证其在光学微纳增材制造中的潜力。所得结果表明，在硫醇-环氧热固化反应中，环氧亚麻籽油作为双酚A二缩水甘油醚的生物基替代品是合适的。与紫外光固化的硫醇-烯聚合物相比，双固化热固性材料表现出更高的刚性、拉伸强度和杨氏模量值，并且在所有制备的聚合物中具有最高的热稳定性。LDW结果证明了它们适用于高分辨率3D打印——对于植物基材料，单个特征达到了前所未有的100 nm。最后，对生物基树脂进行了热后处理测试，并实现了50%的特征尺寸缩小。
