Swift heavy ion irradiation effects on Carbonyl and transvinylene groups in high and low density polyethylene

M. F. DEL GROSSO; V. C. CHAPPA; C. ARBEITMAN; G. GARCÍA BERMÚDEZ

Buenos Aires

Conferencia; At the frontiers of Condensed Matter IV; 2008

<!-- /* Font Definitions */ @font-face {font-family:TimesNewRomanPS-BoldMT; panose-1:0 0 0 0 0 0 0 0 0 0; mso-font-charset:0; mso-generic-font-family:roman; mso-font-format:other; mso-font-pitch:auto; mso-font-signature:3 0 0 0 1 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> Polyethylene is the most widely used polymer and several desirable application properties can be obtained by choosing one of a large variety of its grades. Some works have investigated the local transformation induced by ion-beam irradiation and it has been found that irradiation in polyethylene produced crosslinking, trans-vinylene, end-vynil, vinylidine and carbonyl groups [1].   In previous works we have studied physico-chemical changes in ultra high molecular weight polyethylene (UHMWPE) due to swift heavy ion irradiation [2].  Fourier Transform Infrared (FTIR) analysis of the irradiated samples showed that, with different ions, the absorbance of the C=C stretching vibration from trans-vinylene groups containing hydroperoxides presents a maximum at certain ion fluence that is correlated with the electronic stopping power. In other work we found that the decreasing part of the absorbance curve after the maximum, is not related to overall destruction of the polymer that appear at higher fluences [3].   Our purpose was to study the creation and destruction of two functional groups and its relation with the material density and the ion energy. To this end, we have studied the effects of high energy irradiation on the physico-chemical modification of high and low density polyethylene (HDPE and LDPE) irradiated with 47 MeV Li, 12 MeV C and 6.7 MeV He as a function of fluence. The thickness samples were 10 μm to assure that the ions passed completely through the material.     From the FTIR spectra were analyzed the modification on trans-vinylene and carbonyl groups with fluence. Creation and damage cross section for these groups were compared for three different PE densities.