Author

Mehta

Date of Award

8-1975

Degree Name

Master of Arts

Department

Chemistry

First Advisor

Dr. George Lowry

Second Advisor

Dr. James A. Howell

Third Advisor

Dr. Herbert D. Warren

Access Setting

Masters Thesis-Open Access

Abstract

Introduction

The heat of polymerization ∆Hp, of Alpha-methylstyrene (AMS) has been a source of study for many years. The structure of AMS is shown in Figure 1.

Roberts and Jessup carried out the first quantitative work to determine ∆Hp if AMS.1 Their data displayed a ∆Hp dependence on the degree of polymerization, DP. Several other reports were also published with new values for ∆Hp and new explanations for the apparent DP dependence.2, 3, 4, 5.

Samples of dimers of AMS have been prepared by various workers.6, 7, 8 The reactions were mostly carried out by using sulfuric acid as an initiator. It has been shown that in carbon tetrachloride solution the polymerization by anhydrous stannic chloride will produce dimer with a cyclic endgroup at the ceiling temperature.9 By regulating the solvent system and initiator concentration, it may be possible to optimize the production of one isomer and exclude the other isomers.

The original outline for this thesis called for carrying out the oligomerization of AMS by using anhydrous stannic chloride as initiator. Gel permeation chromatography can be used to separate a mixture of oligomers. Preparative column chromatography could be used to obtain samples of pure dimer. The identification of isomers of dimer called for use of various spectroscopic methods. Once a pure sample of dimer having a known amount of a particular isomer, is obtained its true heat of polymerization can be determined.

The structure of the "cyclic" isomer, 1, 3, 3-trimethyl -1-phenyl indane, has been established previously.10

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Chemistry Commons

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