Naslov
In-Source Analysis of Radiation Curing of Unsaturated Polyester Resin by Charging Current Technique

Autori
Jelčić, Želimir ; Ranogajec, Franjo ; Pucić-Miličić, Irina

Izvornik
International journal of radiation applications and instrumentation. Part C, Radiation physics and chemistry (1359-0197) 36 (1990), 3; 461-466

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Polyester resins ; Curing ; Cure monitoring ; Radiation effects ; Vitrification

Sažetak
The decrease in dielectric permittivity and in charging current may be mainly associated with the partial immobilization of permanent carbonyl and hydroxyl dipoles attached to the oligoester chain. The measurement of charging properties of UP resins during the curing seems very promising due to the ease with which the relaxation parameters and essential information on the molecular interactions and mobility can be derived. The electrical properties of UP resins are mainly determined by inter- and intramolecular hydrogen bonds. The shape of the charging current spectra during the curing of UP resins showed a heterogeneous nature of vitrification process. The results show that two relaxations occur: the first one is attributed to the increase in viscosity of liquid phase as oligoester chains are crosslinked prior to the gelation, and the second one to the further crosslinking in the gel phase, resulting in the vitrification of the system. The characteristic times to gelation and vitrification of UP resins in the course of radiation isothermal curing are decreasing functions of reaction temperatures.

Izvorni jezik
Engleski

Znanstvena područja
Kemijsko inženjerstvo

POVEZANOST RADA