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Infrared-spectroscopical Polymer Identification. 1790-1720. very strong . no. yes. 1610-1590, 1600-1580 and 1510-1490. 1610 –1590, 1600 – 1580 and 1510 - 1490. All numbers have the meaning of wave numbers and are given in cm -1. 3500 - 3200. 840 - 820. 3500 - 3200. 1680 - 1630.
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Infrared-spectroscopical Polymer Identification 1790-1720 very strong no yes 1610-1590, 1600-1580 and 1510-1490 1610 –1590, 1600 – 1580 and 1510 - 1490 All numbers have the meaning of wave numbers and are given in cm-1 3500 - 3200 840 - 820 3500 - 3200 1680 - 1630 strong 1450 -1410 sharp strong 1450 - 1410 sharp 1550 - 1530 1100 - 1000 Alkylsilicone, aliphatic hy= drocarbons, Polytetra= Fluorethylene, Thiokol Alkyd-, Polyesters, Cellulose= ether, PVC (plasticized) Acrylics, Polyester Polystyrenes, Arylsilicones, Aryl-alkyl= Silicone Co= polymers Polyamides, amines Nitrocellulose cellophan Cellophan, Alkylcellulose, PVA, PEO Modif. Epoxies Polycarbo= nates Polyvinyl= acetate, PVC-copo= lymers Cellulose= ester Polyure= thane Phenol derivatives, Epoxies PAN, PVC, Polyvinyliden chlorid, POM
Determination of a Layer Thickness Intensity, arbitrary units wave length 1/d= 2/n (1/l1 -1/l2) n = number of minima between two maxima l1and l2
1790-1720 cm-1 3500-3200 cm-1 1680-1630 cm-1 1550-1530 cm-1 epoxies, polycarbonate,alkyd resins, polyesters, cellulose-ether, PVC poly(vinyl acetate), PVC-copoly., cellulose ester, PU acryl polymers 1610-1590 1600-1580 cm-1 1510-1490 Phenol resins, epoxies, aryl polymers Polyamid
1610-1590 1600-1580 cm-1 1510-1490 820-840 cm-1 1790-1720cm-1 modified epoxides, polycarbonate, Alkyd resins, polyester, cellulose ester, cellulose ether, PVC (plast), PVAc, PVC-copolym., PU, acrylics modified epoxides, polycarbonate, Alkyd resins, polyester, cellulose ester, cellulose ether, PVC (plast) Modified epoxies, polycarbonate polycarbonate
? typical pattern of PU polycarbonate typical pattern of normal PC C-O-C-ether region ? cellulose ester or polyurethane ? 1610-1590 1600-1580 cm-1 1510-1490 1100-1000 cm-1 1450-1410 cm-1 Poly (ether urethane)
Infrared Spectroscopy: l = 760 nm….1mm near infrared “quartz-infrared” ~ 10,000…4,000 cm-1 NIR middle infrared “conventional” infrared ~4,000…250 cm-1 far infrared < 250 cm-1 use of quartz cuvettes and light pipes higher order absorptions (lower intensity) liquids can be measured in thicker layers
NIR • Hydrogen-containing groups are dominant • Information is often implicid, coupled vibrations • Not suited for trace analysis • Easy analysis of aqueous solutions • Process-analysis • Use of light-pipes even without cuvette (reflection) • Easy analysis of powders using diffuse reflection • Characterisation of fillers • Determination of water contents in liquids and solids
4000 cm-1…50 cm-1 fundamental vibrations 4000 cm-1…400 cm-1 fundamental vibrations 12500 cm-1…4000 cm-1 overtones & combinations scattering absorption absorption monochromatic excitation source dispersed polychromatic radiation information from scattered radiation information from absorbed radiation homonuclear functionalities changes in polarizability polar functionalities changes in dipol moment CH/OH/NH functionalities high structural selectivity high structural selectivity low structural selectivity Lambert-Beer-Law Lambert-Beer-Law Iraman~ c sample preparation required (except ATIR) no sample preparation required no sample preparation required sample volume µL sample thickness µm sample volume µL sample thickness µm sample thickness up to cm-range light-fibre optics >100 m light-fiber optics >100 m limited Raman NIR MIR
2D-Spectroscopy (general scheme) general pertubation mechanical, electric, electro-magnetic, chemical,… dynamic spectrum system Electro-magnetic probe IR X-ray, UV-vis, NMR,… 2D-correlation spectrum
2 dimensional correlation vibrational spectroscopy Samples are exposed to external pertubations such as: temperature pressure stress Resolution (the large number of) overlapping NIR bands can be enhanced and MIR and NIR correlation spectra are very useful for peak assignement