Infrared, Fourier transform blends

The role of specific interactions in the plasticization of PVC has been proposed from work on specific interactions of esters in solvents (eg, hydrogenated chlorocarbons) (13), work on blends of polyesters with PVC (14—19), and work on plasticized PVC itself (20—23). Modes of iateraction between the carbonyl functionaHty of the plasticizer ester or polyester were proposed, mostly on the basis of results from Fourier transform infrared spectroscopy (ftir). Shifts in the absorption frequency of the carbonyl group of the plasticizer ester to lower wave number, indicative of a reduction in polarity (ie, some iateraction between this functionaHty and the polymer) have been reported (20—22). Work performed with dibutyl phthalate (22) suggests an optimum concentration at which such iateractions are maximized. Spectral shifts are in the range 3—8 cm . Similar shifts have also been reported in blends of PVC with polyesters (14—20), again showing a concentration dependence of the shift to lower wave number of the ester carbonyl absorption frequency. 

Principal component analysis has been used in combination with spectroscopy in other types of multicomponent analyses. For example, compatible and incompatible blends of polyphenzlene oxides and polystyrene were distinguished using Fourier-transform-infrared spectra (59). Raman spectra of sulfuric acid/water mixtures were used in conjunction with principal component analysis to identify different ions, compositions, and hydrates (60). The identity and number of species present in binary and tertiary mixtures of polycycHc aromatic hydrocarbons were deterrnined using fluorescence spectra (61). 

Evidence of chemical interaction between the mbbers and compatibUizers was demonstrated by extracting the blends with chloroform at room temperamre and examining both soluble and insoluble fractions with Fourier transform infrared (ETIR) spectrometry. The weight of the insoluble fraction of the compatibilized melt blend was more than that in the uncompatibilized blend indicating the formation of (EP-g-MA)-g-CR due to reaction between MA and allylic chlorine of CR. The compounds containing epoxidized EPDM additive were examined by both optical and... 

Lefebvre, D., Jasse, B., Monnerie, L. Fourier Transform Infrared Study of Unaxially Oriented Poly(2,6-dimethyl 1,4-phenylene oxide)-Atactic Polystyrene Blends, submitted to Polymer... 

In this section we discuss a method of controlled material degradation for individual organic semiconductors and also for the blends used in bulk heterojunction solar cells [37]. The degradation is studied using attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and by determining current/voltage characteristics (I/V measurements) of the devices. 

Transition metal coordination of Cu(II) carboxylate groups and pyridine groups was employed as a means of coupling a telechelic butadiene-base polymer with a randomly functionalized styrenic polymer. Dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC) indicated partial miscibility of the two polymers and Fourier transform infrared (FTIR) spectroscopy demonstrated that interactions occurred on a molecular level. When compared with blends of PSVP and the free acid derivative of CTB, the compositions based on the transition metal complex had improved dimensional stability at elevated temperatures, though there remains some question as to the stability of the copper salt to hydrolysis. Electron spin resonance (ESR) spectroscopy showed that only the... 

Degradation was followed by measuring the infrared absorption intensities of the aliphatic and sulfone groups in the chain as a function of dose. Measurements were made on a Perkin Elmer Model 257 grating spectrophotometer and by Fourier Transform infrared spectrometry using a Nicolet 5DX FTIR spectrometer operating at 2 cm-1 resolution. Absorbance spectra of PMPS in novolac/PMPS blends were corrected for the contribution due to novolac absorption by subtraction of an appropriately scaled absorbance spectrum of pure novolac. 

For the studies of interactions in polymer blends the nuclear magnetic resonance (NMR), and Fourier transform infrared spectroscopy (FTIR) are of principal significance. 

Fourier transform infrared (FT-IR) spectroscopy can be used to characterize drug substances, polymer blends, polymer complexes, dynamics, surfaces, and interfaces, as well as chromatographic effluents and degradation products. It provides information about the complexation and interactions between the various constituents in the PECs. It is capable of qualitative identification of the structure of unknown materials as well as the quantitative measurement of the components in a complex mixture. FT-IR spectra of physical mixture and PEC can be determined by FT-IR spectrophotometer using KBr disc method in the range of 4000 to 250 cm h Since the stability and drug substance is very important in several applications, determination of their physicochemical stability is crucial. The FTIR spectra of polyacrylic acid, PVP, metformin hydrochloride, and PEC microparticles of metformin were shown in Figure 56.8. The FTIR spectra of polyacrylic acid and PVP have shown... 

Information regarding the possible interaction between the components in a polymer blend can be obtained by comparison of the infrared spectra of the base material with that of the blends [20,21]. Figures 5.10a and 5.10b represent the typical Fourier transform infrared (FTIR) spectra of PMMA and PMMA/EMA (90/10) blends, respectively. The spectrum of PMMA shows a very sharp peak around 3398 cm due to overtones of stretching vibrations... 

Torikai et aU have y-irradiated poly(styrene-co-methacrylate) copolymers and blends of polystyrene and polymethacrylate. They investigated the influence of irradiation on PMMA by ultraviolet and Fourier transform infrared spectroscopies and by viscosity measurements. In the case of the blends, the degradahon of the PMMA is similar to that awaited. No shielding effect... 

A series of composites of polystyrene (PS) and block poly(styrene-butadiene) (SBS) prepared by extrusion blending in the injection screw and injection moulding were studied by Fourier transform infrared (FTIR) analysis. Moulded samples were then dissolved and cast as a film and again studied using FTIR, with higher levels of miscibility noted than on the original moulding. SBS content of the samples was between 20 and 80 percent, with studies also completed on the pure polymers. Differences observed from simulated spectra of the polymer composites were explained by interactions between the two polymers due to partial miscibility. Corroboration of results was provided by calorimetry studies. 16 refs. 

Fourier transform infrared microspectroscopy is applied for the characterisation of a coated interface and a polymer blend. The coated sample investigated is prepared by coating a urethane paint on an ethylene-ethyl acrylate copolymer whose ethyl-ester group is partially hydrolysed (EAA/EEA). It is demonstrated that a mixed phase is formed along the coated interface between the paint and the EAA/EEA. Interaction between molecules of the urethane paint and the EAA/EEA is observed. For a polymer blend prepared by mixing PP and polycarbonate. 

Ethylene-vinyl acetate copolymer, terpene-phenol resins, polyethylene oxide, PMMA and some of their blends were solution cast on basic (aluminium oxide) and acidic (hydroxylated glass) substrates. Fourier transform infrared reflection absorption spectroscopy (IRRAS) was used to determine both the nature and the free energy of interfacial adduct formation in the polymer/metal systems. A correlation between IRRAS and adhesive strength may be used to predict both the acid-base work of adhesion and the density of interfacial interacting sites. 14 refs. 

Surface modification in order to improve the hydrophilicity of membrane surface can be achieved by blending surface modifying macromolecules to the base material. Blends of phenolphthalein poly(ether sulfone) and poly(acrylonitrile-co-acrylamido methylpropane sulfonic acid), a material that contains charged groups, have been prepared [76]. It was found that the charged groups tend to accumulate onto the membrane surface using X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. 

An example of blending was when phenylcarbomylated or azido phenylcarbo-mylated p-CD was successfully blended with polymethyl methacrylate (PMMA) and electrospun into nanofibrous membranes for organic waste treatment and water purification (Kaur et al. 2006). The presence of the p-CD derivatives on the surface of the nanofibers was confirmed by attenuated total reflectance-Fourier transform infrared spectrometry (ATR-FTIR) and x-ray photoelectron spectroscopy (XPS). A solution containing phenolphthalein (PHP) was used to determine the ability of the functionalized membranes to capture small organic molecules. The results showed... 

The films obtained were characterized for miscibility by DSC, tensile testing and fourier transform infrared spectroscopy spectroscopy. DSC measurements showed that the glass transition temperature associated to PLA and PVB are not dependent on the composition of the blend. Two glass transition temperatures in the blends indicate an knmiscibility of the base materials. Mechanical analysis showed that the tensile strength and elongation decreased due to blending (23). 

Scott et a/., carried out Fourier transform infrared and electron spin resonance spectroscopic investigations of the photopolymerization of vinyl ester resins These consisted of studying reaction kinetics during photopolymerization of bis glycol methacrylate/styrene blends using commercial photoinitiators, Irgacure 819 and Lucirin TPO ... 

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