Curing behaviors' characterization of strong and weak crosslinking systems by thermal and dynamic mechanical methods. (September 2018)

• Record Type: Journal Article
• Authors: Liu, Yongchang; Wu, Qiang; Wang, Chong; Zhou, Dunhong; Liang, Rui; Kang, Yang
• Is Part Of: Polymer testing. Volume 70(2018)
• Page Start: 1
• Page End: 7
• Publication Date: 2018-09
• Subjects: Cure reaction -- Differential scanning calorimetry (DSC) -- Dynamic shear rheometer (DSR) -- Dicyandiamide -- Epoxy asphalt; Polymers -- Testing -- Periodicals; Polymères -- Tests -- Périodiques; 620.1920287
• DOI: 10.1016/j.polymertesting.2018.06.022
• Languages: English
• ISSNs: 0142-9418

Abstract

Abstract: Curing processes of weak- and strong-crosslinking curing systems, e.g., epoxy asphalt and dicyandiamide cured epoxy resin systems, were studied by mechanical method of dynamic shear rheometer (DSR) and thermal method of differential scanning calorimetry (DSC), respectively. Results indicate that the two approaches are both sensitive to the whole curing process for strong-crosslinking system, whose curing exothermic process matches its mechanical properties' development. But for weak-crosslinking system, i.e., incompletely cured rubber-like one, whose mechanical properties' improvement lags behind its curing exothermic process, DSC is sensitive in initial stage of curing reaction, and DSR is sensitive after gel point. Furthermore, with Avrami equation, it is possible to control the curing processes for preparing products with needed mechanical properties by DSR. Therefore, although DSC method is classical, DSR and alike mechanical methods should be comprehensively evaluated in terms of involved curing systems at different curing stages as well as researchers' study purposes. Highlights: DSC and DSR are both sensitive to whole curing process of strong-crosslinking system. For weak-crosslinking system, DSR is sensitive after gelation. DSR is helpful to control curing process for obtaining needed mechanical properties.