Slonov Azamat, Musov Ismel, Zhansitov Azamat, Khashirov Azamat, Tlupov Aslanbek, Musov Khasan, Rzhevskaya Elena, Fomicheva Irina, Potapov Andrey, Khashirova Svetlana
Laboratory of Technology of Polymer Materials and Composites, Tula State University, Prospekt Lenina 92, 300012 Tula, Russia.
Progressive Materials and Additive Technologies Center, Kabardino-Balkarian State University Named after H.M. Berbekov, St. Chernyshevsky, 173, 360004 Nalchik, Russia.
Polymers (Basel). 2023 Oct 18;15(20):4129. doi: 10.3390/polym15204129.
3D printing of polyolefins, such as polyethylene (PE) and polypropylene (PP), is of great practical interest due to the combination of high properties of these materials. However, the use of these materials in 3D printing is associated with many problems due to their high rate of crystallization, which causes shrinkage and warpage of the printed object. In this regard, blends of PE and ethylene-vinyl acetate copolymer (EVA) of various compositions were investigated for 3D printing. It was found that with an increase in the concentration of EVA, an increase in the pseudoplastic effect and amorphization of PE occurs. It has been shown that with an increase in the EVA content, the degree of crystallinity of PE decreases slightly (by 11% at a content of 80% EVA); however, a significant decrease in the rate of crystallization of PE is observed (by 87.5% at the same EVA concentration). It was found that PE and EVA are completely compatible in the amorphous phase and partially compatible in the crystalline phase, which leads to a slight decrease in the melting point of PE. The introduction of EVA also leads to a significant increase in impact strength: the maximum value is achieved at a 50/50 ratio, which is five times the value of the initial PE and two times the value of the initial EVA. At the same time, it was revealed that EVA leads to a gradual decrease in the elastic modulus and strength of PE, the change of which generally obeys the additivity rule. The resulting printing filaments are characterized by a certain ovality due to their shrinkage, which decreases with increasing EVA content and reaches a minimum value at a PE/EVA ratio of 30/70. This composition also demonstrates the lowest shrinkage of the printed sample and higher processability during printing.
聚烯烃（如聚乙烯（PE）和聚丙烯（PP））的3D打印因其材料的高性能组合而具有极大的实际意义。然而，由于这些材料的高结晶速率，在3D打印中使用它们会带来许多问题，这会导致打印物体的收缩和翘曲。在这方面，研究了各种组成的PE与乙烯-醋酸乙烯酯共聚物（EVA）的共混物用于3D打印。研究发现，随着EVA浓度的增加，PE的假塑性效应增强且发生非晶化。结果表明，随着EVA含量的增加，PE的结晶度略有下降（EVA含量为80%时下降11%）；然而，观察到PE的结晶速率显著下降（在相同EVA浓度下下降87.5%）。研究发现，PE和EVA在非晶相中完全相容，在晶相中部分相容，这导致PE的熔点略有下降。引入EVA还会导致冲击强度显著提高：在50/50的比例下达到最大值，是初始PE值的五倍，初始EVA值的两倍。同时，研究表明EVA会导致PE的弹性模量和强度逐渐下降，其变化总体上遵循加和规则。由于收缩，所得打印丝具有一定的椭圆度，随着EVA含量的增加而减小，在PE/EVA比例为30/70时达到最小值。该组成还显示出打印样品的收缩率最低，且在打印过程中具有更高的加工性能。
