Degradation kinetics of polymers in solution: Time-dependence of molecular weight distributions. [Quarterly report, January--March 1996] Metadata

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Title

  • Main Title Degradation kinetics of polymers in solution: Time-dependence of molecular weight distributions. [Quarterly report, January--March 1996]

Creator

  • Author: McCoy, B.J.
    Creator Type: Personal
  • Author: Madras, G.
    Creator Type: Personal

Contributor

  • Sponsor: United States. Department of Energy.
    Contributor Type: Organization
    Contributor Info: USDOE, Washington, DC (United States)
  • Sponsor: Environmental Protection Agency, Washington, DC (United States)
    Contributor Type: Organization

Publisher

  • Name: California Univ., Davis, CA (United States). Dept. of Chemical Engineering and Materials Science
    Place of Publication: United States

Date

  • Creation: 1996-02-27

Language

  • English

Description

  • Content Description: Polymer degradation occurs when polymer chains are broken under the influence of thermal, mechanical, or chemical energy. Chain-end depolymerization and random- and midpoint-chain scission are mechanisms that have been observed in liquid-phase polymer degradation. Here we develop mathematical models, unified by continuous-mixture kinetics, to show how these different mechanisms affect polymer degradation in solution. Rate expressions for the fragmentation of molecular-weight distributions (MWDs) govern the evolution of the MWDs. The governing integro-differential equations can be solved analytically for realistic conditions. Moment analysis for first-order continuous kinetics shows the temporal behavior of MWDs. Chain-end depolymerization yields monomer product and polymer molecular-weight moments that vary linearly with time. In contrast, random- and midpoint-chain scission models display exponential time behavior. The mathematical results reasonably portray experimental observations for polymer degradation. This approach, based on the time evolution of continuous distributions of chain length or molecular weight, provides a framework for interpreting several types of polymer degradation processes.
  • Physical Description: 27 p.

Subject

  • Keyword: Polymers
  • Keyword: Progress Report
  • Keyword: Mathematical Models
  • Keyword: Thermal Degradation
  • Keyword: Chemical Reaction Kinetics
  • Keyword: Depolymerization
  • STI Subject Categories: 40 Chemistry
  • Keyword: Molecular Weight

Source

  • Other Information: PBD: 27 Feb 1996

Collection

  • Name: Office of Scientific & Technical Information Technical Reports
    Code: OSTI

Institution

  • Name: UNT Libraries Government Documents Department
    Code: UNTGD

Resource Type

  • Report

Format

  • Text

Identifier

  • Other: DE96050320
  • Report No.: DOE/PC/94204--T8
  • Grant Number: FG22-94PC94204
  • DOI: 10.2172/382447
  • Office of Scientific & Technical Information Report Number: 382447
  • Archival Resource Key: ark:/67531/metadc677184

Note

  • Display Note: OSTI as DE96050320