ISSN:
1572-8943
Keywords:
autoacceleration
;
dynamic rheometry
;
gelation
;
gel effect
;
TMDSC
;
unsaturated polyester resin
;
vitrification
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract The free radical cross-linking copolymerization of an unsaturated polyester resin with styrene is studied in isothermal conditions using temperature modulated differential scanning calorimetry (TMDSC) and dynamic rheometry. The dynamic rheometry measurements show that gelation occurs at a conversion below 5%, while TMDSC measurements show that an important autoacceleration starts near 60% conversion, giving rise to a maximum cure rate closely before the (partial) vitrification of the system near 80%. This indicates that the autoacceleration is not due to the sharp increase in bulk viscosity at gelation, but rather to a change in molecular mobilities at higher conversion.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1010112718501
