Basar Ozkan, Veliyath Varghese Paul, Tarak Fatih, Sabet Ehsan
Wolfson School of Mechanical, Electrical & Manufacturing Engineering, Loughborough University, Loughborough LE11 3TU, UK.
Additive Manufacturing Centre of Excellence, 33 Shaftesbury Street South, Derby DE23 8YH, UK.
Polymers (Basel). 2023 Jul 24;15(14):3141. doi: 10.3390/polym15143141.
Additive ceramics manufacturing with vat-photopolymerisation (VP) is a developing field, and the need for suitable printing materials hinders its fast growth. Binder mixtures significantly influence the mechanical properties of printed ceramic bodies by VP, considering their rheological properties, curing performances and green body characteristics. Improving mechanical characteristics and reducing cracks during printing and post-processes is mainly related to binder formulations. The study aims to develop a binder formulation to provide the printed ceramic specimens with additional green strength. The impact on mechanical properties (ultimate tensile strength, flexural strength, Young's and strain at breakpoint), viscosity and cure performance of Urethane Acrylate (UA) and thermoplastic Polyether Acrylate (PEA) oligomers to monofunctional N-Vinylpyrrolidone (NVP), 1,6-Hexanediol Diacrylate (HDDA) and Tri-functional Photocentric 34 (PC34) monomers were investigated under varying concentrations. The best mechanical characteristic was showcased when the PC34 was replaced with 20-30 wt.% of UA in the organic medium. The Thermogravimetric Analysis (TGA) and sintering test outcomes revealed that increasing the content of NVP in the organic medium (above 15 wt.%) leads to uncontrolled thermal degradation during debinding and defects on ceramic parts after sintering. The negative effect of UA on the viscosity of ceramic-loaded mixtures was controlled by eliminating the PC34 compound with NVP and HDDA, and optimum mechanical properties were achieved at 15 wt.% of NVP and 65 wt.% of HDDA. PEA is added to provide additional flexibility to the ceramic parts. It was found that strain and other mechanical parameters peaked at 15 wt.% of PEA. The study formulated the most suitable binder formulation on the green body strength of printing silica ceramics as 50 wt.% HDDA, 20 wt.% Urethane Acrylate, 15 wt.% NVP and 15 wt.% PEA.
基于光固化（VP）的添加剂陶瓷制造是一个不断发展的领域，而对合适打印材料的需求阻碍了其快速发展。考虑到粘合剂混合物的流变特性、固化性能和生坯特性，它们会显著影响通过VP打印的陶瓷体的机械性能。在打印和后处理过程中改善机械特性并减少裂纹主要与粘合剂配方有关。该研究旨在开发一种粘合剂配方，为打印的陶瓷试样提供额外的生坯强度。研究了在不同浓度下，聚氨酯丙烯酸酯（UA）和热塑性聚醚丙烯酸酯（PEA）低聚物对单官能N-乙烯基吡咯烷酮（NVP）、1,6-己二醇二丙烯酸酯（HDDA）和三官能光引发剂34（PC34）单体的机械性能（极限拉伸强度、弯曲强度、杨氏模量和断裂应变）、粘度和固化性能的影响。当在有机介质中用20-30 wt.%的UA替代PC34时，展现出了最佳的机械特性。热重分析（TGA）和烧结测试结果表明，在有机介质中增加NVP的含量（超过15 wt.%）会导致脱脂过程中不受控制的热降解以及烧结后陶瓷部件出现缺陷。通过用NVP和HDDA消除PC34化合物，控制了UA对含陶瓷混合物粘度的负面影响，并且在15 wt.%的NVP和65 wt.%的HDDA时实现了最佳机械性能。添加PEA是为了给陶瓷部件提供额外的柔韧性。发现应变和其他机械参数在15 wt.%的PEA时达到峰值。该研究确定了用于打印二氧化硅陶瓷生坯强度的最合适粘合剂配方为50 wt.% HDDA、20 wt.%聚氨酯丙烯酸酯、15 wt.% NVP和15 wt.% PEA。
