{"@context":"https://schema.org","@type":"ScholarlyArticle","headline":"Cooking schedule of alkyd resin preparation. Part II. Effect of cooking schedule on molecular weight distribution of alkyd resin","author":[{"@type":"Person","name":"Takumi Nagata"}],"datePublished":"1969","isPartOf":{"@type":"Periodical","name":"Journal of Applied Polymer Science"},"identifier":"https://doi.org/10.1002/APP.1969.070131208","description":"AbstractThe 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.","url":"https://innscience.ca/es/community/literature/a601f258-18f0-4a36-ba58-8ef1e74c2746"}