In the present paper the relationship between chemical reactions and energy deposition mechanisms is investigated for PMDA-ODA thin films. The chemical reactions at the polymer surface and near-surface are studied by XPS technique. The effects induced by using 5 keV Ar0 and 3 keV electrons are compared with those produced by heat treatments up to about 1000-degrees-C. In particular, we found that Ar0 bombardment induces some simultaneous chemical mechanisms of decomposition, involving the random destruction of the monomer units. A specific reaction involving recoiling oxygen atoms has been identified. Contrary to this, the deposition of the same amount of total energy by electron irradiation seems to induce only one decomposition mechanism, consisting in the elimination of the whole imidic ring. Finally, thermal pyrolysis promotes several consecutive reactions, mainly involving decarbonylation of the imidic rings, while the phenyl rings and the ether linkages are relatively stable. The experiments show the existence of recognizable ''nonconventional'' chemical reactivity, whose character, in this case, seems mainly related to the collisional term of the energy loss.
Heat-induced versus particle-beam-induced chemistry in polyimide
IACONA F
1993
Abstract
In the present paper the relationship between chemical reactions and energy deposition mechanisms is investigated for PMDA-ODA thin films. The chemical reactions at the polymer surface and near-surface are studied by XPS technique. The effects induced by using 5 keV Ar0 and 3 keV electrons are compared with those produced by heat treatments up to about 1000-degrees-C. In particular, we found that Ar0 bombardment induces some simultaneous chemical mechanisms of decomposition, involving the random destruction of the monomer units. A specific reaction involving recoiling oxygen atoms has been identified. Contrary to this, the deposition of the same amount of total energy by electron irradiation seems to induce only one decomposition mechanism, consisting in the elimination of the whole imidic ring. Finally, thermal pyrolysis promotes several consecutive reactions, mainly involving decarbonylation of the imidic rings, while the phenyl rings and the ether linkages are relatively stable. The experiments show the existence of recognizable ''nonconventional'' chemical reactivity, whose character, in this case, seems mainly related to the collisional term of the energy loss.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
