Effects of additives and morphology on space charge in LDPE

The effects of additives and morphology on space charge in various LDPEs have been investigated. Antioxidants, by-products of the cross-linking and oxidation products enhanced space charge in LDPE. The space charge also depended upon the physical structure (or density) of LDPE and the process of polymerization. Injected space charge moved more easily in LDPE with a lower density and it decayed more quickly after the short-circuit. The space charge distributions were affected by electrode material, temperature and applied field. The X-ray induced TSC revealed that the origins of some carrier traps are physical defects such as cavities formed by the local arrangement of molecular chains. This is one of reasons why space charge in LDPE is closely related to its physical structure (morphology)