THE RELATIONSHIPS BETWEEN POLYMERS AND GLASS TRANSITION TEMPERATURES

reportActive / Technical Report | Accession Number: AD0649869 | Open PDF

Abstract:

The glass transition is an experimental manifestation of the extremely large activation energies for molecular motion encountered as the temperature of a liquid is lowered. As an approach to the effect of molecular structure on this phenomenon, low-shear melt viscosities were obtained as a function of temperature for three homologous series of polymers polypropylene, polychlorotrifluorethylene and polypropylene oxide. A kinetic model of the glass transition was devised for computer simulation of dilatometric behavior in the region of a transition. The assumption that the dielectric and volume relaxation times are equal was shown to be satisfactory for prediction of dilatometric results on polymers. The effects of rate of heating, activation energy and coefficients of expansion on the measurement of transitions were demonstrated. The Gibbs-DiMarzio theory of the glass transition was cast in a form suitable for very short chains and shown to agree quantitatively with To values for the lower n-alkanes. The Eyring transition state theory of relaxation processes was shown to be applicable to dielectric relaxation in polymers with modification to allow for a temperature-dependent activation free energy.

Author(s):
Lewis, O. G. ; Gallacher, L. V.
Author Organization(s):
AMERICAN CYANAMID CO STAMFORD CT CENTRAL RESEARCH DIV
Descriptive Note:
Technical rept. for Jun 1965-May 1966
Supplementary Note:
Rept. for 'Fundamental Research on Macromolecular Materials and Lubrication Phenomena'. See also AD-620734.
Pagination:
0073

Security Markings

DOCUMENT & CONTEXTUAL SUMMARY

Distribution:
Approved For Public Release, Document Partially Illegible
Distribution Statement:
Availability: Document Partially Illegible.

RECORD

Collection: TR
Identifying Numbers
Report Number(s):
AFML-TR-65-231-PT-2
Contract/Grant Number(s):
AF 33(657)-11224
Task Number(s):
734203
Project Number(s):
AF-7342
Monitor Series:
TR-65-231-PT-2, AFML
 Subject Terms
Joint Capability Areas:
JCA_3.2_Engagement; JCA_3_Force Application; JCA_3.2.1_Kinetic Means; JCA_5_Command and Control; JCA_5.3_Planning; JCA_1.2.7_Experimentation; JCA_1.3_Human Capital Management; JCA_1_Force Support; JCA_6_Net Centric; JCA_1.3.2_Personnel Management; JCA_JCA_4.1.2_Sustain the Force; JCA_4.1_Deployment and Distribution
Modernization Areas:
Microelectronics
Communities of Interest:
Advanced Electronics
Descriptor(s):
*POLYMERS, *HALOGENATED HYDROCARBONS, *EPOXY RESINS, *POLYETHYLENE PLASTICS, PHASE STUDIES, GLASS, CHEMICAL BONDS, DIELECTRIC PROPERTIES, TRANSITION TEMPERATURE, THERMAL EXPANSION, HEATING, MOLECULAR STRUCTURE, RELAXATION TIME, VISCOSITY, FREE ENERGY, HEAT OF ACTIVATION
Field(s)/Group(s):
Polymer Chemistry, Atomic and Molecular Physics and Spectroscopy
Report Date:
1966 Jul 01