MIL-PRF-23942A(AS)
a. Make the polymer solution up to the final volume and shake thoroughly. Fill the 1,500-
µm sample cell. Fill the reference cell with the same stock carbon disulfide used to make the
solution. Make a complete spectrum of the 1,500-µm sample cell with the reference cell in the
reference beam. Normal operating conditions may be used, although a slower scanning speed
may be used if desirable. If the transmission at the band maximum of either the 10.35 or 11.0 µm
band is less than 20 percent, scan the sample in the 500-µm cell.
b. Measurement of spectra. Measure all absorbencies for the trans and vinyl bands at the
band maxima (see 6.4.3). Draw the baselines as shown on figure 1. Calculate the absorbance, A,
as follows:
A = log Io - log I
Where Io and I are measured as shown on figure 1. Make this measurement accurately.
4.5.6.4 Calculations.
a. Calculate the trans and vinyl concentrations as follows:
Percent unsaturation = 100 A
abc
Where:
A = measured absorbance
a = absorptivity as determined under calibration
b = cell thickness in centimeters
c = polymer concentration, g/L
b. Calculate the cis concentration from the relation:
percent cis = 100 - (T + V)
Where:
T = percent trans
V = percent vinyl
4.5.6.5 Calibration. If the short method is to be used with the same instrument on which the
complete method (see 6.4.4) has been calibrated, no additional spectra are required. If a different
instrument is to be used, measure the samples selected as calibration standards on it also.
Preferably, measure near the same time as the samples for the complete method and in the same
cells. If this is not possible, purify the samples and prepare new solutions. Measure baseline
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