Grytsenko Oleksandr, Dulebova Ludmila, Spišák Emil, Berezhnyy Bohdan
Department of Chemical Technology of Plastics Processing, Lviv Polytechnic National University, 12, St. Bandera Str., 79013 Lviv, Ukraine.
Department of Technologies, Materials and Computer Aided Production, Technical University of Kosice, 74 Mäsiarska, 04001 Kosice, Slovakia.
Materials (Basel). 2022 Jul 26;15(15):5183. doi: 10.3390/ma15155183.
The article investigates the peculiarities of the effect of ferromagnetic fillers (FMFs) of various natures (Ni, Co, Fe, FeCo, SmCo) on the formation of the structure and properties of 2-hydroxyethylmethacrylate (HEMA) with polyvinylpyrrolidone (PVP) copolymers. The composites were characterized using FTIR-spectroscopy, SEM, DMTA, magnetometry of vibrating samples, specific electrical resistivity studies, and mechanical and thermophysical studies. The formation of a grafted spatially crosslinked copolymer (pHEMA-gr-PVP) was confirmed and it was established that the FMF introduction of only 10 wt.% into the copolymer formulation increased the degree of crosslinking of the polymer network by three times. The surface hardness of composites increased by 20-25%. However, the water content decreased by 16-18% and lay within 42-43 wt.%, which is a relatively high number. The heat resistance of dry composites was characterized by Vicat softening temperature, which was 39-42 °C higher compared to the unfilled material. It was established that the obtained composites were characterized by a coercive force of 200 kA × m and induction of a magnetic field at the poles of 4-5 mT and 10-15 mT, respectively. The introduction of FMF particles into pHEMA-gr-PVP copolymers, which, in the dry state, are dielectrics, provides them with electrical conductivity, which was evaluated by the specific volume resistance. Depending on the FMF nature and content, as well as their orientation in the magnetic field, the resistance of filled materials could be regulated within 10-10 Ohm·m. Therefore, the modification of HEMA with PVP copolymers by ferromagnetic fillers of various natures provides the possibility of obtaining materials with unique predicted properties and expands the fields of their use, for instance as magnetic sorbents for various applications, as well as the possibilities associated with their being electrically conductive materials that can respond by changing of electrical conductivity, depending on various factors.
本文研究了不同性质的铁磁填料（FMF，包括Ni、Co、Fe、FeCo、SmCo）对甲基丙烯酸2-羟乙酯（HEMA）与聚乙烯吡咯烷酮（PVP）共聚物结构和性能形成的影响特点。采用傅里叶变换红外光谱（FTIR）、扫描电子显微镜（SEM）、动态热机械分析（DMTA）、振动样品磁强计、比电阻率研究以及力学和热物理研究等方法对复合材料进行了表征。证实了接枝空间交联共聚物（pHEMA-gr-PVP）的形成，并确定仅在共聚物配方中引入10 wt.%的FMF可使聚合物网络的交联度提高三倍。复合材料的表面硬度提高了20 - 25%。然而，含水量降低了16 - 18%，处于42 - 43 wt.%的范围内，这一数值相对较高。干燥复合材料的耐热性通过维卡软化温度来表征，与未填充材料相比，该温度高出39 - 42℃。已确定所获得的复合材料的矫顽力为200 kA×m，磁极处的磁场感应强度分别为4 - 5 mT和10 - 15 mT。将FMF颗粒引入到在干燥状态下为电介质的pHEMA-gr-PVP共聚物中，使其具有导电性，通过比体积电阻对其进行评估。根据FMF的性质和含量以及它们在磁场中的取向，填充材料的电阻可在10 - 10欧姆·米范围内调节。因此，用不同性质的铁磁填料对HEMA与PVP共聚物进行改性，为获得具有独特预测性能的材料提供了可能性，并扩展了其应用领域，例如作为各种应用的磁吸附剂，以及作为可根据各种因素通过改变电导率做出响应的导电材料所具有的可能性。
