Lakatos Ákos, Csík Attila
Department of Building Services and Building Engineering, Faculty of Engineering, University of Debrecen, Ótemető Str 2-4, 4028 Debrecen, Hungary.
Institute for Nuclear Research, Bem tér 18/c, 4026 Debrecen, Hungary.
Polymers (Basel). 2022 Apr 14;14(8):1606. doi: 10.3390/polym14081606.
Nowadays, to improve quality of life, to have a more comfortable life, in internal spaces we try to maintain conditions that are free from external environmental influences. Thus, existing as well as newly built houses have adequate interiors maintaining their temperature, warming, or cooling due to the environment compensation. One way to create this is to reduce the heat loss in buildings. An option to achieve this is the application of thermal insulations. Nowadays, the use of super insulation materials such as aerogel and vacuum insulation panels and other nano-structured insulations, such as graphite doped expanded polystyrene, is becoming increasingly justified. These are relatively new materials, and we know only a little about them. This paper presents research results based on temperature-induced investigations of nanostructured graphite expanded polystyrene, to reveal its thermal stability after long-term and short-term thermal annealing, simulating the ageing of the material. Firstly, with a differential scanning calorimeter, we will explore the thermal stability profile of the specimens. After this, the paper will present temperature-induced changes in both the thermal properties and the structure of the samples. We will also present changes in the thermal conductivity, modifications in the surface, and compressive property variation induced by thermal annealing. The samples were thermal annealed at 70 °C for 6 weeks, at 100 and 110 °C for 1 h. Besides the thermal conductivity measurements with Netzsch 446 heat flow meter equipment, we will present specific heat capacity measurement results executed with the same equipment. Moreover, sorption isotherms of the as-received and annealed samples were registered and completed with hydrophobic experiments, too. Furthermore, from the measurements, we showed that temperature should affect a significant change in the thermal conductivity of materials. Moreover, the changes in the graphite expanded polystyrene before and after thermal annealing were investigated by Scanning Electron Microscopy, as well as optical microscopy. The structural changes were further followed by an X-ray diffractometer and the IR absorption capability was tested, too.
如今，为了提高生活质量，拥有更舒适的生活，在室内空间我们试图维持不受外部环境影响的条件。因此，现有房屋以及新建房屋都有适宜的内部环境，通过环境补偿来保持温度、取暖或制冷。实现这一点的一种方法是减少建筑物的热损失。实现这一目标的一个选择是应用隔热材料。如今，使用气凝胶和真空隔热板等超级隔热材料以及其他纳米结构隔热材料，如石墨掺杂膨胀聚苯乙烯，变得越来越合理。这些是相对较新的材料，我们对它们了解甚少。本文基于对纳米结构石墨膨胀聚苯乙烯的温度诱导研究呈现研究结果，以揭示其在长期和短期热退火模拟材料老化后的热稳定性。首先，使用差示扫描量热仪，我们将探究试样的热稳定性曲线。在此之后，本文将呈现温度诱导的样品热性能和结构变化。我们还将呈现热退火引起的热导率变化、表面改性以及压缩性能变化。样品在70℃下热退火6周，在100℃和110℃下热退火1小时。除了使用耐驰446热流计设备测量热导率外，我们还将呈现使用同一设备进行的比热容测量结果。此外，还记录了原样和退火样品的吸附等温线，并完成了疏水性实验。此外，从测量结果来看，我们表明温度会对材料的热导率产生显著变化。此外，通过扫描电子显微镜以及光学显微镜研究了热退火前后石墨膨胀聚苯乙烯的变化。通过X射线衍射仪进一步跟踪结构变化，并测试了红外吸收能力。
