Naslov
Postirradiation Crosslinking And Structure Of Unsaturated Polyester Resin

Autori
Pucić, Irina ; Jurkin, Tanja

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
7th Austrian Polymer Meeting / - Graz, 2005

Skup
7th Austrian Polymer Meeting

Mjesto i datum
Graz, Austrija, 04.07.2005. - 06.07.2005

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
unsaturated polyester resin; postirradiation crosslinking; DSC; NMR; extraction analysis; microgel

Sažetak
The polyester resins are easily crosslinked by ionising radiation that induces formation of free radicals. At the interruption of the irradiation significant part of free radicals remain unreacted so crosslinking can proceed to the extent that depends on number of parameters. To determine the magnitude of postirradiation crosslinking, the measurements were performed on selected days after the irradiation on two different commercial unsaturated polyester resin samples to chosen doses. The sensitivity of three experimental techniques to postirradiation crosslinking was evaluated. FTIR showed the lowest sensitivity towards postirradiation reaction, some changes were detected by extraction analysis including determination of free styrene content. Substantial changes were detected for more than five days after irradiation by differential scanning calorimetry (DSC) that showed highest sensitivity to post-reaction. The last two techniques were able to detect the influence of particular reaction period at which the irradiation was interrupted and the differences in polyester resin samples reactivity on postirradiation crosslinking. One of the resins, A, showed pronounced reaction induced phase separation that significantly influenced postirradiation reaction course. The styrene and polyester are miscible in relatively narrow concentration range and the formation of polyester rich spherical entities, microgels, at the beginning of crosslinking, as third component further disrupts homogeneity of the reaction system. NMR spectra revealed that the reaction induced phase separation occurred in resin with phtalic acid included into polyester chain, while isophtalic acid, added to polyester of resin I allowed better compatibility with styrene resulting in almost no phase separation and higher postirradiation conversion.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA