[article]
Titre : |
Esterification of ethylene glycol and polyethylene glycol modified shellac for high class indutrial finishes |
Type de document : |
texte imprimé |
Auteurs : |
Deepti Shikha, Auteur ; P. K. Kamani, Auteur |
Année de publication : |
1999 |
Article en page(s) : |
p. 31-42 |
Note générale : |
Bibliogr. |
Langues : |
Anglais (eng) |
Tags : |
'Matériau revêtement' Vernis Liant 'Gomme laque' modifié' Ethane-1,2-diol 'Ethylène oxyde polymère' Estérification Formulation 'Propriété mécanique' Feuil 'Etude expérimentale' |
Index. décimale : |
667.9 Revêtements et enduits |
Résumé : |
Shellac, a natural resin in which India holds the monopoly by producing about 80% of the world's production, is very well known for some of its properties. Of course there are some drawbacks associated with shellac which have limited their application. In order to remove these drawbacks of shellac varnishes, shellac-glycol compounds from shellac, ethylene-glycol, and polyethylene glycols were prepared. Phosphorous penta-oxide has been used as the catalyst. Two series of compounds, first containing shellac-ethylene glycol and the second shellac-ethylene and polyethylene glycol mixture, were prepared by esterifying with various monobasic acids from safflower oil, isomerised linseed oil, dehydrated castor oil, tung oil, rosin and rosin modified products. Each series comprises of eleven samples (Twenty two in all). Varnishes from these esterified products were prepared to study and to evaluate the film properties. These varnishes were then tested according to I.S. Specifications. It was observed that tung oil fatty acid varnishes exhibited the best results followed by the varnishes from dehydrated castor oil and isomerised linseed oil fatty acids. Safflower oil fatty acids varnishes have also been found satisfactory. Varnishes from rosin and rosin modified products were the least satisfactory. Both the series yielded products of almost parallel film forming properties such as baking period, hardness, flexibility, resistance to various chemicals, etc. Out-door exposure test of the films had also been carried out. Furthermore, the results of exposure test have shown that the compositions containing fatty acids possess better weather resistance than those having rosin or rosin modified products. The modified shellac is understood to have commercial application in the present scenario. |
Note de contenu : |
- HISTORY
- STRUCTURE
- PREPARATION : Preparation of shellac-glycol compounds (shellac etylene-glycol compound, shellac-polyethylene glycol compound) - Esterification of shellac-glycol componds with various acids - Preparation of varnishes and their evaluation |
Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=12972 |
in PAINTINDIA > Vol. XLIX, N° 6 (06/1999) . - p. 31-42
[article]
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