Characterization of structural changes of poly(vinyl methyl ether) gamma-irradiated in diluted aqueous solutions

Langmuir. 2004 Mar 30;20(7):2883-9. doi: 10.1021/la030349a.

Abstract

An aqueous deoxygenated dilute PVME solution (cP = 0.5 mass %) was irradiated with gamma-rays at different radiation doses (D = 0.2-10 kGy). At these concentrations and doses contracted molecules are formed but no macroscopic networks. For the analysis of the structural changes, the irradiated samples were analyzed by size exclusion chromatography (SEC) with a triple detector system, static light scattering, and viscometry. SEC measurements necessitate for the application of the universal calibration principle the knowledge of the Kuhn-Mark-Houwink (KMH) parameters. To obtain these parameters commercially available poly(vinyl methyl ether) was fractionated and analyzed by the same means. We found at 30 degrees C a KMH relationship to [eta] = 0.0226 (mL/g) x Mw(0.67) in THF. We observed an increase in molar masses without any significant structural changing for D < 0.5 kGy. With increasing radiation dose, the intramolecular cross-linking reaction becomes more and more important. The results of viscosity measurements show a slight increase in contraction for 1.0 kGy. For irradiation dose higher than D > 1.5 kGy, a strong contraction occurs. For D > 5.0 kGy, the favored intramolecular reactions lead to the formation of microgels.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Gamma Rays
  • Methyl Ethers* / chemistry
  • Methyl Ethers* / radiation effects
  • Polyvinyls* / chemistry
  • Polyvinyls* / radiation effects
  • Solutions / chemistry
  • Surface Properties
  • Water / chemistry

Substances

  • Methyl Ethers
  • Polyvinyls
  • Solutions
  • Water