ISSN:
1435-1536
Schlagwort(e):
Key words Bisphenol A epoxy resin
;
Waterborne dispersions
;
Phase-inversion emulsification
;
Electrical properties
;
Rheological behavior
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Chemie und Pharmazie
,
Maschinenbau
Notizen:
Abstract Waterborne dispersions of bisphenol A epoxy resin were prepared by the so-called phase-inversion emulsification technique. The electrical properties, rheological behavior and morphological evolution during the phase inversion process were characterized systematically. It was shown that both emulsifier concentration and emulsification temperature play great roles in controlling the phase inversion process as well as the structural features of the waterborne particles. A high emulsifier concentration, i.e. 10.90 wt% and a low emulsification temperature, i.e. 73 °C, facilitate complete phase inversion, in which all water droplets in the system are simultaneously transformed into the continuous phase at the phase-inversion point (PIP). In this case, sub-micron-sized, discrete waterborne particles were formed. In contrast, a complex water-in-oil-in-water structure was achieved by incomplete phase inversion at a low emulsifier concentration, i.e. 2.33 wt%, and a high temperature of 80 °C. The morphological evolution observed by scanning electron microscopy revealed that not all the water droplets in the system were converted into the continuous phase at the PIP and that some small water drops were trapped within the waterborne structure.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/s003960000375
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