Cremer Julian, Kaltschmidt Bernhard P, Kiel Annika, Eberhard Jens, Schmidt Stephan, Kaltschmidt Christian, Kaltschmidt Barbara, Hütten Andreas, Anselmetti Dario
Department of Experimental Biophysics & Applied Nanoscience, Faculty of Physics, Bielefeld University, 33615 Bielefeld, Germany.
Department of Thin Films and Physics of Nanostructures, Center of Spinelectronic Materials and Devices, Faculty of Physics, Bielefeld University, 33615 Bielefeld, Germany.
Polymers (Basel). 2023 Feb 28;15(5):1247. doi: 10.3390/polym15051247.
The performance of plastic components in water-bearing parts of industrial and household appliances, often in the presence of harsh environments and elevated temperatures, critically relies on the mechanical and thermal polymer stability. In this light, the precise knowledge of aging properties of polymers formulated with dedicated antiaging additive packages as well as various fillers is crucial for long-time device warranty. We investigated and analysed the time-dependent, polymer-liquid interface aging of different industrial performance polypropylene samples in aqueous detergent solution at high temperatures (95 °C). Special emphasis was put on the disadvantageous process of consecutive biofilm formation that often follows surface transformation and degradation. Atomic force microscopy, scanning electron microscopy, and infrared spectroscopy were used to monitor and analyse the surface aging process. Additionally, bacterial adhesion and biofilm formation was characterised by colony forming unit assays. One of the key findings is the observation of crystalline, fibre-like growth of ethylene bis stearamide (EBS) on the surface during the aging process. EBS is a widely used process aid and lubricant enabling the proper demoulding of injection moulding plastic parts. The aging-induced surface-covering EBS layers changed the surface morphology and promoted bacterial adhesion as well as biofilm formation of .
工业和家用电器含水部件中的塑料部件，通常在恶劣环境和高温条件下，其性能严重依赖于聚合物的机械和热稳定性。有鉴于此，精确了解添加专用抗老化添加剂包和各种填料的聚合物的老化特性，对于延长设备保修期限至关重要。我们研究并分析了不同工业性能聚丙烯样品在高温（95°C）的水性洗涤剂溶液中的随时间变化的聚合物-液体界面老化情况。特别关注了表面转变和降解后经常出现的连续生物膜形成这一不利过程。使用原子力显微镜、扫描电子显微镜和红外光谱来监测和分析表面老化过程。此外，通过菌落形成单位测定来表征细菌粘附和生物膜形成。关键发现之一是在老化过程中观察到乙烯双硬脂酰胺（EBS）在表面呈晶体状、纤维状生长。EBS是一种广泛使用的加工助剂和润滑剂，可使注塑塑料部件顺利脱模。老化诱导的覆盖表面的EBS层改变了表面形态，促进了细菌粘附以及生物膜的形成。
