Poly carbonyl stretching band

The carbonyl stretching band in the infrared spectrum of isotactic poly (a,a-dimethylbenzy 1 methacrylate) prebaked at 142°C for 1 hr indicated the formation of a small amount of acid group during the prebake, while the atactic polymer showed no change in the spectrum at this temperature. This may be the reason why the isotactic polymer showed a lower 7-value than the atactic polymer (Table III). 

The variation of the functional monomer concentration is reflected in the PA-FllK spectra of the miniemulsion products. An increasing of the HEMA content in the polymer composite can be seen at the signiflcant carbonyl stretching band at 1600 cm which increased in the spectra from product 1 to product 3 with increasing of the HEMA content in the monomer composition. Nevertheless, next to the typical copolymer bands for poly(S-co-HEMA), signiflcant silica core bands are visible in all spectra. The monomer com-... 

Figure 15 FT-Raman spectra of fake ivory specimens (a) carved X ctorian bangle, (b) large bangle, (c) small bangle, (d) cal. The absence of the characteristic proteinaceous features in true ivory near 1650 and 1450 cm and the strong phosphate mode near 960 cm" should be noted. Also, the presence of the aromatic ring bands at 3060, 1600, and 1000 cm" in (b) and (d) indicate a polystyrene resin content, whereas the carbonyl stretching band at 1725 cm" in all fake specimens indicates the presence of poly(methyl methacrylate). In the cat specimen, the band at 1086 cm uniquely identifies a calcite additive in the specimens of imitation ivory studied. (Reproduced with permission from HGM Edwards, DW Farwell. Ivory and simulated ivory artifacts Fourier-transform Raman diagnostic study. Spectrochimica Acta, Part A, 51 2073-2081. 1995, Elsevier Science B.V.)...

Evaluation of IR spectra of acrylonitrile-butadiene-styrene (ABS) after UV irradiation shows that rubber double bands at 965 cm and 910 cm (Fig. 3.65), attributed to poly(trans-l,4-butadiene) and poly(l,2-butadiene), respectively, decrease with exposure time (Fig. 3.66) in a first order reaction, together with the carbon-carbon double stretching band at 3450 cm in addition, a saturated carbonyl band (centred at 1725 cm ) forms (Fig. 3.65) by a first order process (Fig. 3.67). During the initial stages of the photooxidation, bands at 1665, 1685 and 1699 cm due to a- and ) -unsaturated carbonyl groups, develop [1113,1936]. 

Fourier-Transform Raman Spectroscopy (FTR) was used to characterize a homologous series of aliphatic poly(anhydrides), poly(carboxyphenoxy)al-kanes, and copolymers of carboxyphenoxy propane (CPP) and sebacic acid. All anhydrides show two diagnostic carbonyl bands, the aliphatic polymers has the carbonyl pairing at 1803/1739 cm 1, and the aromatic polymers have the band pair at 1764 and 1712 cm -1. All the homo- and copolymers showed methylene bands due to deformation, stretching, rocking and twisting the spectra for the... 

Characterization of poly(HEMA-co-(PVA-MA)) hydrogel. The IR spectra of Poly(HEMA-co-(PVA-MA)) is shown in Figure 2. A strong absorption band at 1720 cm l, corresponding to Ae stretching mode of carbonyl group of ester, could be found. In addition, a broader absorption band around 3500 cm"l appeared due to Ae presence of carboxylic acid in PVA-MA. 

The formation of the latter complexes can be followed by infrared spectroscopy, as it involves a proton transfer from the acid of poly (acrylic acid) to the tertiary amine of the mesogens. Complexation results in a significant reduction, or almost complete elimination, for the equimolar complexes, of the acid carbonyl band near 1700 cm and the appearance of a new band near 1550cm attributed to the asymmetric carboxylate stretch. The residual carbonyl absorption that remains in the equimolar mixtures indicates the presence of a small... 

Many published studies consider cases in which one of the components contains an accessible carbonyl group, the stretching vibration band of which broadens and shifts to lower wavenumber in the presence of a second compatible polymer (see an example in Figure 4.10). Recent examples of thermal and spectroscopic analyses of blend systems include poly(vinyl acetate) (PVA) with PMMA [184] poly(vinylidene fluoride) (PVDF) with PVA [185, 186] polybenzimidazole/poly(bisphenol-A-carbonate) [187] andPMMA-fluorinated polymer blends [188]. All these make use of spectral subtraction routines to observe interactions, but additional data-processing tools have also been used to aid understanding, such as Fourier self-deconvolution [188],... 

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