|
I. INTRODUCTION - THE OPACITY PROBLEM AND IT'S SOLUTIONS... |
1 |
|
|
II. PHOTOACOUSTIC SIGNAL GENERATION............................................. |
1 |
|
|
A. Signal Generation Model........................................................................... |
1 |
|
|
B. Variation of Sampling depth....................................................................... |
4 |
|
|
III. INSTRUMENTATION................................................................................. |
5 |
|
|
A. Photoacoustic Detector............................................................................. |
5 |
|
|
B. FTIR Spectrometer................................................................................... |
8 |
|
|
C. System Checks......................................................................................... |
9 |
|
|
IV. SAMPLE HANDLING................................................................................. |
10 |
|
|
A. General Considerations............................................................................. |
10 |
|
|
B. Sample Loading........................................................................................ |
10 |
|
|
V. FTIR-PAS METHODS FOR SPECIFIC ANALYSES.................................. |
13 |
|
|
A. Qualitative Analysis of Macrosamples....................................................... |
13 |
|
|
1. Polymer identification by computer search.............................................. |
13 |
|
|
2. Adhesive spectrum by spectral subtraction............................................. |
16 |
|
|
B. Qualitative Analysis of Microsamples........................................................ |
18 |
|
|
1. Single tectile fibers................................................................................. |
18 |
|
|
2. Single coal particles................................................................................ |
22 |
|
|
C. Quantitative Analyses................................................................................ |
24 |
|
|
1. Vinyl acetate concentration in polyethylene copolmer
pellets................... |
26 |
|
|
2. Ash concentration in coal....................................................................... |
26 |
|
|
D. Variation of Sampling Depth..................................................................... |
30 |
|
|
1. Homogeneous polycarbonate................................................................ |
30 |
|
|
2. Mylar-coated polycarbonate.................................................................. |
31 |
|
|
3. Cure of an acrylic coating....................................................................... |
32 |
|
|
4. Plastic-coated paper.............................................................................. |
33 |
|
|
5. Chemicall-treated surfaces of polystyrene............................................... |
35 |
|
|
E. Carbon-Filled Materials............................................................................. |
35 |
|
|
1. Composite material prepreg................................................................... |
36 |
|
|
2. Automobile tire...................................................................................... |
37 |
|
|
F. Polymer Films........................................................................................... |
37 |
|
|
1. Elimination of interference fringes by FTIR-PAS.................................... |
37 |
|
|
2. Polarized beam measurements on oriented films..................................... |
38 |
|
|
3. Polymer coatings on metal containers..................................................... |
40 |
|
|
G. Semi-solids, Gels, and Liquids.................................................................. |
41 |
|
|
VI. CONCLUSION............................................................................................ |
42 |
|
|
VII. ACKNOWLEDGEMENTS......................................................................... |
42 |
|
|
VIII. REFERENCES........................................................................................... |
43 |
