METAL-COMPLEX MODIFICATION OF SEGMENTED POLYURETHANES

In recent years, there has been a significant increase in interest in creating polymeric materials that have not only high mechanical characteristics, but also functional properties, in particular, reduced values of the specific volume electrical resistance. Such materials are widely used as components of flexible electronics, elements of sensor systems, antistatic agents and precision membranes. Segmented polyurethanes (SPU) with phase-separated morphology, which makes it possible to precisely regulate their structure and properties, are promising for influencing electrophysical properties and are practically significant. In this paper, we investigated metal complex modifiers (MC) of segmented polyurethanes based on Cu(II) chloride complexes with N,N'-diethylhydroxylamine, which promote the appearance of exchange charge transfer centers, which leads to a decrease in the specific volume electrical resistance of polyurethanes (MSPU) modified using MC by several orders of magnitude. The lowest values of volume electrical resistance for segmented polyurethanes modified with MC are achieved already at its very low content, which is in the range of 0.1-0.5 wt.% of copper (II) chloride introduced as part of MC. It is shown that an increase in the length of the rigid block in MSPU leads to a noticeable increase in the ρv values. The effect of the molar ratio of the initial components in the metal complex system on the ρv values of MSPU is studied. The lowest ρv values are achieved at a molar ratio of Cu(II) chloride to N,N′-diethylhydroxylamine of 1:1. Coordination bonding using a low MC content leads to an increase in the transition temperature to the viscous-flow state from 160 °C for unmodified segmented polyurethane to 185 °C for MSPU containing 0.1 wt.% of copper (II) chloride introduced as part of MC. It is concluded that significant orientation processes in the polymer matrix of MSPU are induced by coordination binding. Since 0.1 wt.% copper (II) chloride relative to the content of hard segments in the molar ratio approaches 1:100, it can be concluded that such coordination binding has a cooperative effect and the explanation of this requires further research.