Make a film by evaporating a drop or 2 of the solvent on a salt plate.
Place a few drops of this solvent-based sample solution on the PLC-11M Prism Cell and
evaporate to leave a thin film of the sample material on the ZnSe prism.
Scan the sample and process normally.
If the sample is FLAT and can be cut, use an ATR (Attenuated Total Reflectance) accessory
(Buck Models 57, 59 or PLC-11M) with a Zinc Selenide (ZnSe) or KRS-5 prism crystal.
Take a background scan on the EMPTY & CLEAN crystal first, then lay the sample against the
crystal and squeeze down tightly without damaging the crystal. Scan the sample and process
normally.
If the sample is malleable (non-thermosetting), try pressing a small fragment in a clean KBr
DIE to create a thin film; then scan directly in transmission.
If the sample will melt or flow, try heating 2 metal plates (or use the dies of the mini-press),
place a small fragment of the sample on the hot metal and squeeze to produce a thin film. Scan
directly in transmission.
5. For NATURAL RUBBERS and FUSIBLE PLASTIC materials =
If the material is soluble in hot SOLVENT, prepare a CAST FILM of the sample by dissolving
small cuttings or shavings of the Polymer in a test tube or small beaker of warm solvent (use a
water bath on a hotplate). Swirl to keep material moving & speed dissolution.
Make a film by evaporating a drop or 2 of the solvent on a salt plate.
Place a few drops of this solvent-based sample solution on the PLC-11M Prism Cell and
evaporate to leave a thin film of the sample material on the ZnSe prism.
Scan the sample and process normally.
Prepare a film of sample PYROLYSATE by heating 1-5 grams of chopped material in the
bottom of a long Pyrex test tube and letting the vapors condense on the upper part of the tube.
Take this condensate and spread on a salt plate with a wooden application (toothpick).
Scan directly in transmission.
If the sample is FLAT and can be cut, use an ATR (Attenuated Total Reflectance) accessory
(Buck Model 57, 59, or PLC-11M) with a Zinc-Selenide (ZnSe) or KRS-5 prism crystal.
Take a background scan on the EMPTY & CLEAN crystal first, then lay the sample against the
crystal and squeeze down tightly without damaging the crystal. Scan the sample process
normally.
6. General Considerations for Formed POLYMERS and PLASTICS =
Poly-CARBONATES and Poly-STYRENES can be selectively attacked by hot solvents and
run as a CAST FILM or in a SEALED LIQUID CELL (0.015 – 0.05 mm path are good). Run
a Background scan on solvent(s) used.
Natural RUBBERS, Synthetic RUBBERS, NYLONS (and general Poly-AMIDES), Poly-
ethylenes and Poly-propylenes, and some PHTHALATE resins can be done by controlled
Pyrolysis. A small burner flame, or even a hotplate is recommended for good recovery (and
less decomposition) of the low molecular weight and thermally labile components.
Do not let the evolving vapors coming out of the mouth of the tube catch fire, since this will
affect the composition of the condensate that will collect in the cool part of the tube. Try to
perform each pyrolysis under the same conditions (time, temperature) for best reproducibility.
Don’t let pyrolysate sit on the crystal too long.
NYLONS, ALKYD Resins and some ACTYLATES can be partially hydrolyzed or dissolved
in aqueous mineral acids (Hydrochloric Acid) and then extracted to get the material into
suitable solvent solutions.
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