Accession Number : ADA429253


Title :   Molecular Transport Mechanisms for Associating and Solvating Penetrant in Polymers


Descriptive Note : Final progress rept. 1 Dec 1999-30 Mar 2003


Corporate Author : MARYLAND UNIV COLLEGE PARK


Personal Author(s) : Barbari, Timothy A.


Full Text : http://www.dtic.mil/get-tr-doc/pdf?AD=ADA429253


Report Date : 30 JUN 2003


Pagination or Media Count : 6


Abstract : The long-term objective of this research is to develop structure-property relationships for the diffusion of associating and solvating penetrants in polymers, which can be used to guide the selection or synthesis of polymers for use as protective barriers or separation membranes. The immediate objective of this project was to understand, using FTIR-ATR spectroscopy, how penetrant-penetrant and penetrant-polymer interactions, particularly hydrogen bonding, dictate transport rates through polymers using model experimental systems and appropriate transport models. There were three specific goals for this project: (1) determine transport mechanisms for associating penetrants in polymers, (2) determine transport mechanisms for penetrants that solvate with groups in the polymer, and (3) determine transport mechanisms in polymers for two penetrants capable of solvation with each other. Respectively, the systems studied to achieve each specific goal were as follows: (1) acetic acid in polyisobutylene; (2) methyl ethyl ketone in vinyl alcohol/vinyl butyral copolymers, and acetonitrile and deuterated hexane, separately, in H12MDI polyurethanes; and (3) mixtures of methyl ethyl ketone and butanol in polyisobutylene. In each case, the spectroscopic technique was able to identify the actual diffusing species and elucidate the mechanisms of diffusion at the molecular level. A list of 16 papers submitted or published under ARO sponsorship during the project is included.


Descriptors :   *HYDROGEN BONDS , *POLYMERS , *TRANSPORT PROPERTIES , *MOLECULE MOLECULE INTERACTIONS , *DIFFUSION , *DIFFUSION COEFFICIENT , *SOLVATION , METHYL RADICALS , ACETONITRILE , TRANSITION TEMPERATURE , POLYMERIC FILMS , BARRIERS , MEMBRANES , MOLECULAR STRUCTURE , BUTENES , POLYURETHANE RESINS , ETHYL RADICALS , KETONES , FOURIER SPECTROSCOPY , HEXANES , ACETIC ACID , BUTANOLS.


Subject Categories : PHYSICAL CHEMISTRY
      POLYMER CHEMISTRY
      ATOMIC AND MOLECULAR PHYSICS AND SPECTROSCOPY
      THERMODYNAMICS


Distribution Statement : APPROVED FOR PUBLIC RELEASE