DETERMINATION OF GLOBAL EXTRACTIVES IN POLYETHYLENE TEREPHTHALATE BY HEATING THE SOLVENT IN A MICROWAVE OVEN By Anuj Vinodchandra Parikh The purpose of this research is to evaluate a method of determining extractives. Instead of a conventional oven, a microwave oven is used to heat the solvent. Attempts are made to duplicate the extraction methodology proposed by the Food and Drug Administration (FDA) in a way that it can be used to determine extractives for microwave-only packages. A test package consisting of crystalline polyethylene terephthalate and paper was selected for the test. A product consisting of a dehydrated mix of pasta and cheese sauce was evaluated to determine the test parameters including the solvent, time, and temperature. Distilled deionized water was selected as a solvent. It was exposed in two different package shapes to counter any microwave heating irregularities. The solvent was heated in packages for 10 minutes in a 700 watt microwave oven at maximum power. The extractives, in each case, were obtained by evaporating the solution under reduced temperature of 60°F (15.5°C) and in vacuum, a method commonly referred to as vacuo. A Rotavapor machine was used for this purpose. The extractives were then dried and weighed. They were further dissolved in chloroform. Chloroform-insoluble extractives were filtered out and further extraction was performed on the solution. The temperature was maintained at 35°F (1.7°C). It was found that the amount of extractives obtained by the conventional FDA method were comparable to the ones obtained by this procedure. In both cases the amount of total extractives for this package fell within the specified limits set by the FDA in milligrams per square inch of contact surface.
Library of Congress Subject Headings
Plastics in packaging--Research; Food--Packaging--Research; Polyethylene--Testing; Solvent extraction--Research
Department, Program, or Center
Packaging Science (CAST)
Parikh, Anuj, "Determination of Global Extractives in Polyethylene Terephthalate by Heating the Solvent in a Microwave Oven" (1988). Thesis. Rochester Institute of Technology. Accessed from
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