Accession Number : ADA187371

Title :   Molecular Motion and Energy Migration in Polymers.

Descriptive Note : Periodic rept. no. 5, Jul-Dec 84,

Corporate Author : ROYAL INSTITUTION OF GREAT BRITAIN LONDON (ENGLAND)

Personal Author(s) : Phillips, David

PDF Url : ADA187371

Report Date : Dec 1984

Pagination or Media Count : 8

Abstract : Work has continued on three fronts, that of the study of excimer formation in styrene polymers, using laser excitation of the fluorescence; the study of time resolved anisotropy in synthetic polymers and model systems, and on the study of structure fluorescence correlation in poly(diacetylenes). Excimer Formation in Copolymers of Styrene and Acrylonitrile; The photophysical behaviour of a range of styrene-acrylonitrile (S-A) copolymers have been studied both by steady state and time resolved fluorescence spectroscopy. The objective of the work was to establish the applicability of the photophysical model which has been proposed to describe intramolecular excimer formation in other vinyl aromatic copolymer systems. Polymers, dissolved in dichloromethane, were excited by the frequency doubled output of a cavity dumped, mode locked 4W Argon ion laser (Spectra Physics 166). The monomer decay in the homopolymer agreement with previous is adequately described by a dual exponential function in observations on high molar mass material and polystyrenes and block copolymers over a wide range of effective polystyrene molar masses. At relatively low aromatic contents, decays in monomer and excimer regions are adequately described by dual exponential decay functions. At intermediate aromatic compositions both monomer and excimer decays require triple exponential functions.

Descriptors :   *EXCIMERS, *ENERGY TRANSFER, *MOLECULAR ROTATION, ACRYLONITRILE POLYMERS, BLOCK COPOLYMERS, COPOLYMERS, STYRENES, DECAY, EXPONENTIAL FUNCTIONS, ENERGY, MIGRATION, FLUORESCENCE, ANISOTROPY, CHLOROMETHANES, FREQUENCY, METHACRYLATES, ACETYLENES, PHOTOLYSIS, ARGON, EXCITATION, LASERS, MOLECULES, MODELS, PHYSICAL PROPERTIES, ACRYLONITRILE POLYMERS, DECAY, STEADY STATE

Subject Categories : Polymer Chemistry
      Plastics

Distribution Statement : APPROVED FOR PUBLIC RELEASE