No abstract

ZUSAMMENFASSUNG:Die Vernetzung von Polyiithylen durch Elektronenstrahlen in Gegenwart von Acrylsiiureestern mehrwertiger Alkohole als Vernetzer wurde untersucht. Der tatsichliche Gehalt dcr Mischungen an Vernetzer nach der Probeherstellung vor der Bestrahlung ist deutlich geringer, als der eingesetzten Menge entspricht. Der Vcrbrauch an Doppelbindungen wahrcnd der Bestrahlung wurde IR-spektroskopisch bestimmt. Das vernetzte Polyiithylen wurde hydrolytisch gespalten; die dabei am Polymeren zuruckbleibenden Carboxylatgruppen wurden IR-spcktroskopisch ermittclt. Die nach beiden Methoden erhaltenen Werte stimmen gut uberein und zeigen, daO bei der Strahlenvernetzung nur ein Teil der Doppelbindungen des Monomeren mit dem Polyathylen reagiert. SUMMARY:The crosslinking of polyethylene by electron beams in the presence of acrylic esters of multifunctional alcohols is investigated. The analytical procedures for the characterization of the obtained crosslinked polyethylene are described. The.actual amount of crosslinking agent after sample preparation prior to irradiation is obviously smaller than the amount originally added. The consumption of double bonds during irradiation has been determined by IR-spectroscopy. On the other hand, the crosslinked polyethylene has been hydrolysed and the remaining carboxylic groups at the polymer chain have been determined again by IR-spectroscopy. The values obtained by the two methods are in good agreement. They show that during the crosslinking reaction by irradiation only a part of the double bonds of the monomer reacts with polyethylene.

The effects of Ti underlayer (collimated Ti vs. standard Ti) and Al deposition power (12 KW vs. 6 KW) on the electromigration (EM) lifetime of Ti\Al-0.5 wt.%Cu\Ti\TiN stack films were investigated The. (002) texture of standard Ti (s-Ti) was stronger than that of collimated Ti (c-Ti), and the Al (111) texture, grain size distribution, and EM lifetime of Al stack prepared with s-Ti underlayer were also better than those with c-Ti underlayer independent of the Al deposition power. The low power (6 KW) deposition led to better Al (111) texture, larger median grain size, and longer EM lifetime than did high power (12 KW) deposition independent of the type of Ti underlayer. Longer deposition time for low power sputtering allowed more time for the deposited Al atoms to be rearranged at more stable sites and to react with Ti, which resulted in a stronger Al (111) texture, larger median grain size, and a more uniform Ti-Al reaction layer. The (002) texture of the Ti underlayer is closely related to the Al (111) texture which is a major factor affecting EM lifetime.