Impact of Thermal Aging on PVC and Foamed PVDF Jackets in Power-Over-Ethernet Cable Performance

Power-over-Ethernet (PoE) technology, valued for its simplicity, faces challenges with rising power demands, potentially degrading polymeric components in cables and leading to system failures, safety hazards, reduced cable performance and lifespan. In this work, we conducted investigations on thermal degradation and aging of polyvinyl chloride (PVC) and foamed polyvinylidene fluoride (PVDF) jackets in PoE cables using thermogravimetric analysis (TGA) and an environmental chamber, alongside monitoring cable electrical performance. Thermal degradation kinetics of these jackets were analyzed using the Ozawa-Flynn-Wall (OFW) method for non-isothermal experiments and an Arrhenius model for isothermal ones. The derived activation energies were compared, and lifetimes were predicted using the latter method. The foamed PVDF jackets exhibited exceptional durability, with a lifespan exceeding a century even at 150°C, while two PVC jackets were estimated to fail within the expected 20-year lifespan at 75°C. Correlations between cable crosstalk deterioration and jacket aging, along with proposed mechanisms, provide benchmarks for evaluating PoE cable electrical performance over time.