Copolymers spectroscopic analysis

Imaging studies were done on copolymers prepared by the polymer modification route because of the availability of the precursor polymers of various molecular weights. The protected copolymers were compounded with triphenylsulfonium hexafluoroantimonate (13% w/w) in cyclohexanone. One micron thick films were spin coated on NaCl plates, baked at 140°C for 5 minutes to expel solvent and then subjected to infrared spectroscopic analysis before and after exposure. Exposure to 18 mJ/cm2 at 254 nm caused no change in the infrared spectrum. However, when the films were baked at 140°C for 120 sec. following exposure, deprotection was quantitative based on loss of the characteristic carbonate C = O absorption and... 

Copolymer Characterization. Copolymer compositions were determined by elemental analysis and thermal gravimetric analysis. A Perkin-Elmer TGS-2 ther-mogravimetric analyzer, programmed from ambient to 800 C in N2 and air, was used. Spectroscopic analysis of the copolymers was not as useful as elemental analysis and thermal gravimetric analysis measurements for analyzing these copolymers. Viscometric measurements were made in a solution of water and NaCl with a Contraves low-shear viscometer. 

Figure 2. FT-IR Spectroscopic Analysis of Aged and Control Films of the Copolymer I.

European Polymer Journal 33, No.3, March 1997, p.375-9 QUANTITATIVE IR SPECTROSCOPIC ANALYSIS OF ETHYLENE-ACRYLATE COPOLYMERS... 

RAMAN SPECTROSCOPIC ANALYSIS OF THE MICROSTRUCTURES OF BUTADIENE-ACRYLONITRILE COPOLYMERS... 

IR SPECTROSCOPIC ANALYSIS OF JONOL IN POLYETHYLENE AND ETHYLENE-VINYL ACETATE COPOLYMER FILMS... 

Archondouli et al. (2003) studied blends of PC with polyester-type polyurethane using SEM, mechanical properties, DMA, DSC, TGA, ETIR, and NMR. Eormation of copolymer was shown by selective solvent extraction and spectroscopic analysis. 

Samples for Spectroscopic Analysis. Different procedures were used. In all cases polymer powders were allowed to dissolve in water for 1h at room temperature, then the solutions were kept at 5 C for 24 hr to ensure complete dissolution of the polymers. In experiments with hydrophobically-modified NIPAM copolymers, solutions were prepared from aqueous stock solutions (1 g L-i) diluted in deionized water in the desired ratios and amounts. Solutions of PNIPAM-Py/200 and PNIPAM-Na/40 of lower concentration (0.1 g L-i) were prepared and used without further dilution. The polymer solutions were added to a (filtered) liposome suspension in deionized water. The resulting suspensions were allowed to stand at room temperature for 3 hours, unless otherwise indicated. 

At cryogenic temperatures, no concentration changes are expected thus IR spectroscopy can be used to detect transitions in polymers by recording abrupt or discontinuous changes in intensities as a function of temperature. This IR type of molecular dilatometry should indicate the same transitions that are observed in bulk thermal expansion measurements. If certain IR absorptions are related to the various components or morphological structures present, then a probe of the thermal responses of these structures is available. Multiphase and copolymer systems can be easily studied by using IR spectroscopic analysis. 

Spectroscopic analyses are widely used to identify the components of copolymers. Infrared (IR) spectroscopy is often sufficient to identify the comonomers present and their general concentration. Nuclear magnetic resonance (NMR) spectrometry is a much more sensitive tool for analysis of copolymers that can be used to accurately quantify copolymer compositions and provide some information regarding monomer placement. 

Varadaraj R, Branham KD, McCormick CL, Bock J (1994) Analysis of hydrophobi-cally associating copolymers utilizing spectroscopic probes and labels. In Dubin P, Bock J, Davis R, Schulz DN, Thies C (eds) Macromolecular complexes in chemistry and biology. Springer-Verlag, Berlin, p 15... 

---