ZIB

Treffer pro Seite

Treffer 1 - 2 | 2 Treffer

Sortierung

Digitale Medien

Curing reaction of epoxy resins with diamines (1984)

Riccardi, C. C. ; Adabbo, H. E. ; Williams, R. J. J.

New York, NY [u.a.] : Wiley-Blackwell

Journal of Applied Polymer Science 29 (1984), S. 2481-2492

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 0021-8995

Schlagwort(e): Chemistry ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Maschinenbau , Physik

Notizen: The curing reaction of a commercial bisphenol A diglycidyl ether (BADGE) with ethylenediamine (EDA) was studied by differential scanning calorimetry. Different kinetic expressions were found with isothermal (low temperature range) and dynamic (high temperature range) runs. Two competitive mechanisms are shown to be present: an autocatalytic one (activation energy E = 14 kcal/mol) and a noncatalytic path characterized by a second-order reaction with E = 24.5 kcal/mol. At low temperatures both mechanisms took place simultaneously, showing a significant decrease in the reaction rate after the gel point. At high temperatures only the noncatalytic reaction was present, without showing a noticeable rate decrease in the rubber region. Also, a third-order dependence of the glass transition temperature on reaction extent is shown.

Zusätzliches Material: 8 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/app.1984.070290805

Permalink

Bibliothek	Standort	Signatur	Band/Heft/Jahr	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

Digitale Medien

The curing of novolacs with paraformaldehyde (1982)

Adabbo, H. E. ; Williams, R. J. J.

New York, NY [u.a.] : Wiley-Blackwell

Journal of Applied Polymer Science 27 (1982), S. 893-901

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 0021-8995

Schlagwort(e): Chemistry ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Maschinenbau , Physik

Notizen: The curing of novolacs with paraformaldehyde is analyzed with several experimental techniques (DSC, IR, sol fraction) as well as statistical arguments. Results for typical novolacs show that a maximum crosslinking density is attained at a mass ratio mP/mN close to 0.20. However, at mP/mN greater than 0.10, hemiformals appear in the cured product, increasing the amount of extractable formaldehyde. The heat of reaction increases linearly from mP/mN = 0 to 0.15, attaining a maximum value of -ΔH = 98 cal/g novolac at mP/mN ∼ 0.20. The curing kinetics follows an overall second-order law with an activation energy E = 32.5 kcal/mol and a preexponential factor A = 1.1 × 1015 min-1 (both for mP/mN 〉 0.1).

Zusätzliches Material: 5 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/app.1982.070270309

Permalink

Bibliothek	Standort	Signatur	Band/Heft/Jahr	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

Treffer 1 - 2 | 2 Treffer