ISSN:
0021-8995
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
The effect of cooking schedule on the molecular weight distribution of an alkyd resin was investigated. At the molar ratio of 1.03/0.43/1.00 for glycerin, lauric acid, and phthalic anhydride, two kinds of alkyd resin were prepared, one by maintaining the reaction temperature at 170°C for an hour and then raising it up to 230°C (sample I), the other by raising the temperature up to 230°C at a uniform rate of 33°C per 10 min. (Sample II). Sample I and sample II were fractionated into seven or eight fractions by adding n-heptane to 5 wt-% toluene solution at 30°C. Acid valued, hydroxyl value, intrinsic viscosity [η], and the number-averagè molecular weight M̄n were determined. The result showed that the molecular weight distribution curve obtained from sample I was much narrower than that from sample II. In addition, a relation was found between [η] and M̄n conforming to the equation [η] = KMα, where different values of K and α were obtained for sample I and sample II. Based on the differences in the molecular weight distribution curves and in the rate constants for the esterification reactions, glycerin/lauric acid and glycerin/phthalic anhydride at 170°C and 230°C, the mechanism of condensation reaction of short oil alkyd resin was discussed.
Additional Material:
11 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1969.070131208
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