Glass transition measurements by DSC

Journal Article · Thu Sep 01 04:00:00 EDT 1994 · American Society for Testing and Materials, Special Technical Publication

DOI:https://doi.org/10.1520/STP15365S· OSTI ID:136461

Bair, H E ^[1]

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1. AT and T Bell Labs., Murray Hill, NJ (United States). Plastics Research and Engineering Dept.

This is a review of glass transition temperature (T{sub g}) measurements of materials by differential scanning calorimetry (DSC). T{sub g} is noted in DSC derived heat capacity (C{sub p}) plots against temperature as the jump in C{sub p} or ({Delta}C{sub p}) that occurs usually over a temperature interval of a few tens of degrees (C). Under conditions which are normal for DSC experiments it was found that the temperature gradient across and from top to bottom of a 0.6-mm-thick molded disk of polycarbonate (17 mg) was no greater than 0.6C when heated at 15 C/min. Under these conditions a glassy polymer can be scanned for its T{sub g} as defined by its half-vitrification temperature ({1/2} {Delta}C{sub p}) as well as the beginning and end of the transition to within 1 C. DSC T{sub g} measurements are reviewed to show how the location, shape, and magnitude of the transition can be used to characterize the composition and behavior of a wide variety of polymeric materials ranging from homopolymers, blocks, grafts, and blends to networks. Also the effect of molecular weight, plasticizers, aging, crystals, and stress on the T{sub g} of several polymers is re-examined.

• Sponsoring Organization: USDOE
• OSTI ID: 136461
• Report Number(s): CONF-930398--
• Journal Information: American Society for Testing and Materials, Special Technical Publication, Journal Name: American Society for Testing and Materials, Special Technical Publication Journal Issue: 1249; ISSN 0066-0558; ISSN ASTTA8
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
42 ENGINEERING
AGING
ANNEALING
CALIBRATION
CALORIMETRY
COMPATIBILITY
ENTHALPY
GRAFTS
MIXTURES
PLASTICIZERS
POLYMERS
SPECIFIC HEAT
TEMPERATURE DEPENDENCE
TRANSITION TEMPERATURE