DOI
https://doi.org/10.25772/BFW5-6W33
Defense Date
1986
Document Type
Dissertation
Degree Name
Doctor of Philosophy
Department
Chemistry
First Advisor
Robert G. Bass
Abstract
Reactions involving the nucleophilic addition cyclization to activated acetylenes have been employed as a novel route to moderate to high molecular weight polymers. Polypyrazoles (PI to P12) have been prepared from the Michael-type addition cyclization of various aromatic dihydrazines to aromatic dipropynones in m-cresol. The aromatic dihydrazines employed were 4, 4'-dihydrazinodiphenyl ether (4,4' -DHDPE), 4,4 '-dihydrazinodiphenylmethane (4, 4'-DHDPM), and 4, 4' -dihydrazinodiphenyl sulfone (4,4'-DHDPS). The dipropynone sutilized were 1,1’- (1,4-phenylene) bis (3-phenyl- 2-propyn-l-one), (l,4 -PPPO), 1,1’ - (1, 3-phenylene) bis (3 -phenyl- 2 -propyn-l-one), (1,3-PPPO), 1,1 '-(1,4 -phenylene) bis (2 -propyn- l-one), (1,4 -PPO), and 1,1’- (1,3 -phenylene) bis (2 -propyn-l-one), (1,3-PPO).
Polymers (PI -P6) obtained from the phenyl substituted dipropynones (1,3 and 1,4 -PPPO's) had inherent viscosities ranging from 0.15 to 0.33 dL/g. The glass transition temperatures (Tg) ranged from 225 to 261°C as measured by differential scanning calorimetry (DSC). The temperatures of 10% weight loss as measured by thermogravimetric analysis (TGA) ranged from 400 to 500°C in air and 470 to 512°C in nitrogen. In a few cases creasable films were obtained by solution casting from chloroform.
Polymers (P7-PI2) obtained from the unsubstituted dipropynones (1,3 and 1,4 -PPOs) had inherent viscosities ranging from 0.31 to 1.05 dL/ g. The Tg's ranged from 202 to 266°C as measured by DSC. The temperatures of -10% weight loss as measured by TGA ranged from 415 to 483°C in air and 466 to 512° C in nitrogen. In a few cases creasable films were obtained by solution casting from N, N-dimethylacetamide.
Moderate to high molecular weight polypyrazoles were readily prepared by the reaction of aromatic dipropynones with aromatic dihydrazines. In a few cases creasable films were obtained. The Tg's ranged from 202 to 261°C as measured by DSC. The polymers exhibited good thermal stability as measured by TGA.
Reactions involving the nucleophilic addition to activated alkenes have been employed as a route to novel acetylene terminated aspartimides (ATA's). Novel ATA's were prepared by the Michael -type addition of a series of aromatic diamines to two moles of N-(3-ethynylphenyl) maleimide (NEM). NEM was prepared by the condensation reaction of 3-ethynylaniline and maleic anhydride. The aromatic amines utilized were aniline,4,4-diaminodiphenyl methane, 4, 4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 4,4'-bis (3-aminophenoxy) benzophenone, 4,4' -bis (4-aminophenoxyphenyl) sulfone, and 1,1, 3-trimethyl-3, S-bis(4 -aminophenoxy) indane.
The ATA's were characterized by infrared spectroscopy (IR) and 1H nuclear magnetic resonance spectroscopy (NMR). The ATAs were isolated as a mixture of stereoisomers since a chiral carbon is created during addition. No attempt was made to separate the stereoisomers. Using a DSC the heats of reaction (ΔH) of the acetylene groups was measured, the ΔH's ranged from -23.2 to -49.2 kcal /mole presumably depending upon acetylene density (concentration).
Rights
© The Author
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
9-26-2016