標題: Differences in curing behavior of cocured and IPN materials
作者: Lin, MS
Chiu, CC
應用化學系
Department of Applied Chemistry
公開日期: 16-May-2001
摘要: This study addressed the blending and cocuring of resole and epoxy, using NaOH and 4,4'-diaminodiphenylmethane as curing agents. IR band shifts regarding the molecular interactions were investigated with FTIR. Exothermic peak shifts during cocuring reactions were studied with dynamic DSC. Viscosity increases were measured with a Brookfield LVT viscometer at 100 degreesC. The dynamic mechanical properties of the cocured samples were investigated using rheometric dynamic spectroscopy (RDS). Experimental results revealed that the molecular interactions between resole and epoxy resulted in good compatibility as shown by the single damping peak in the RDS curve and the single glass transition for each cocured sample. Also apparent were accelerated curing rates, leading to shifts of the exothermic peaks to lower temperature and faster viscosity increases. Nevertheless, enhanced gel fractions and increased glass-transition temperatures (T-g) of the samples were generally observed for this cocured system. The average molecular weight between crosslinked points calculated for the cocured materials also showed much less than the two components. These curing behaviors were quite different from those of the Interpenetrating Polymer Network (IPN) materials, which usually indicated lowered gel fractions, decreased T-g, and higher average molecular weight between crosslinkings than for components. (C) 2001 John Wiley & Sons, Inc.
URI: http://dx.doi.org/10.1002/app.1177
http://hdl.handle.net/11536/29641
ISSN: 0021-8995
DOI: 10.1002/app.1177
期刊: JOURNAL OF APPLIED POLYMER SCIENCE
Volume: 80
Issue: 7
起始頁: 963
結束頁: 969
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