EQUILIBRIUM CHEMICAL CHARACTERISTICS OF NYLON-ACRYLIC ACID GRAFT COPOLYMER
Abstract
The radiation-grafted polymer of acrylic acid on nylon 6,6 - a fiber with flash- resistant properties, was studied as representative of a new and useful class of textile fibers. The present report covers the first phase of research on the fundamental chemical properties of this fiber. Equilibriumcharacteristics are discussed and results of work on kinetics will follow. Equilibrium studies were made of rapidly-stirred suspensions of finely cut polymer fiber at several temperatures (30 -60C). The base-reactive capacity(potassium hydroxide) was 2.0 milliequivalents per gram at 30C (about twenty times that of the base polymer), with no significant change in capacity at higher temperatures. The acid strength of the copolymer was unexpectedlylow (apparent pKa=9), an effect attributed to a heightened polyelectrolyte effect caused by restricted mobility of the carboxyl groups. Evidence for a conformational transition of the polymer chain at about 55% ionization was shown by a discontinuity in the Henderson- Hasselbach plot of the titration curve. This was attributed to a reversible shifting of the polymer chains. Neutralelectrolyte caused a distinct increase in the apparent acid strength (pKa - 5.8),and a delay in the transition to a point later in the titration (95% neutralized).No effect of temperature on the equilibrium characteristics of the copolymer was observed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1969
- Accession Number
- AD0699340
Entities
People
- Alvin O. Ramsley
- Basil A. Natsios
- Edward M. Healy
Organizations
- United States Army Soldier Systems Center