THE DU PONT THERMAL ANALYSIS SYSTEM EXPANDS AGAIN. MEET THE 940 THERMOMECHANICAL ANALYZER. The Du Pont 9 4 0 TMA is the latest and quite the most unusual module in the 900 Thermal Analysis System. A plug-in module of the Du Pont 900 Differential Thermal Analyzer, the TMA measures both expansion and pene tration of materials as a function of time or temperature. You can use the TMA for laboratory measurements of softening t e m p e r a t u r e s , shrink temperatures, glass transitions and coefficients of linear thermal expansion of a broad range of materials. For example, the top scan at the right shows the softening point and the alpha transition of a polyethylene sample. The sample was in the form of a 1 mil film coated on paper. The data were obtained directly from the coated sample, thus elimina ting any sample pretreatment and resulting unwanted thermal history effects. Expansion measurements are extremely sensitive and can be used to study a variety of phenomena. A striking example is the record shown for expandable polystyrene (bottom scan). The range of application of the material is indicated clearly since the sample expands rapidly starting at 94°C and then suddenly collapses at 129°C. The glass transition at 82°C is also readily seen. When used as an expansion device, the TMA detects dimension changes as small as 2 χ 10~ 5 inches. The 940 TMA has such high sensitivity it can also be used to measure softening of viscous materials like but ter and asphalt. The TMA can handle virtually all solid samples in the form of plugs or films from —120°C to 200°C. For more information about the Du Pont 940 Thermomechanical Analyzer and other laboratory instruments in the Du Pont Thermal Analysis System, write Du Pont, Instrument Products Division-1, Wilmington, Del. 19898.
SAMPLE: POLYETHYLENE-COATED PAPERWARE MODE: PENETRATION LOADING: 5 GRAM , HEATING RATE: 5°C/MINUTE
3.2 χ 10-" in.
a Transition
109°C
60
20
80
100
120
140
TC
SAMPLE: EXPANDABLE POLYSTYRENE MODE: EXPANSION HEIGHT: 0.035" LOADING: 1 GRAM T HEATING RATE: 5°C/MINUTE
:
8.3 χ 1 0 " · in.
40
60
80
100 "PC
120
140
160
DU PONT REG. U.S. PAT. OFF
INSTRUMENTS See ACS Laboratory Guide for All Products/Sales Office
Circle No. 53 on Readers' Service Card
VOL. 39, NO. 4, APRIL 1967
·
73 A
