Polymer resin infrared spectroscopy

As already indicated above, what one may consider a surface depends on the property under consideration. Adhesion is very much an outer atomic layer issue, unless one is dealing with materials like fibreboard in which the polymer resin may also be involved in mechanical anchoring onto the wood particles. Gloss and other optical properties are related to the penetration depth of optical radiation. The latter depends on the optical properties of the material, but in general involves more than a few micrometer thickness and therewith much more than the outer atomic layers only. It is thus the penetration depth of the probing technique that needs to be suitably selected with respect to the surface problem under investigation. Examples selected for various depths (< 10 nm, 10 s of nm, 100 nm, micrometer scale) have been presented in Chapter 10 of the book by Garton on Infrared Spectroscopy of Polymer Blends, Composites and Surfaces... 

A mechanistic study by Haynes et al. demonstrated that the same basic reaction cycle operates for rhodium-catalysed methanol carbonylation in both homogeneous and supported systems [59]. The catalytically active complex [Rh(CO)2l2] was supported on an ion exchange resin based on poly(4-vinylpyridine-co-styrene-co-divinylbenzene) in which the pendant pyridyl groups had been quaternised by reaction with Mel. Heterogenisation of the Rh(I) complex was achieved by reaction of the quaternised polymer with the dimer, [Rh(CO)2l]2 (Scheme 11). Infrared spectroscopy revealed i (CO) bands for the supported [Rh(CO)2l2] anions at frequencies very similar to those observed in solution spectra. The structure of the supported complex was confirmed by EXAFS measurements, which revealed a square planar geometry comparable to that found in solution and the solid state. The first X-ray crystal structures of salts of [Rh(CO)2l2]" were also reported in this study. 

Up-to-date compendiums on applications of infrared spectroscopy in applied polymer science are as follows. "An Infrared Spectroscopy Atlas for the Coatings Industry" (95) describes techniques, has liberal references to specific methods, and contains high-quality grating reference spectra on paint components and blended compositions. "Atlas of Polymer and Plastics Analysis," 2nd ed., by Hummel and Scholl (96), has issued two volumes Vol. 1, Polymers Vol. 3, on Additives and Processing Aids Vol. 2, on Plastics, Fibers, Rubbers, Resins, is in press. "Infrared Spectra of Plasticizers and Other Additives," 2nd ed., published by The Coblentz Society, Inc., is a high-quality IR reference spectrum collection (97). 

The first step in recycling plastics is to sort the plastics by their resin type, or resin identification code. The resin identification code is a number assigned to a plastic product (or container) according to the type of polymers it is made of. While it was once common to directly use this code to identify the types of polymer(s) present, there are now other methods, such as near-infrared spectroscopy or density sorting approaches, that are used to sort mass quantities of plastic samples for recycling. (See Polymer Chemistry for more information on resin identification codes.)... 

Musto, P. Mascia, L. Ragosta, G. Scarinzi, G. Villano, P. (2000). The transport of water in a tetrafunctional epoxy resin by near-infrared Fourier transform spectroscopy. Polymer, Vol. 41, No.2, Qanuary 2000), pp.565-574, ISSN 0032-3057. 

Xu, L.S. Schlup, J.R. (1998). Etherification versus amine addition during epoxy resin amine cure An in situ study using near-infrared spectroscopy. Journal of Applied Polymer Science, Vol.67, No.5, 0anuary 1998), pp. 895-90, ISSN 0021-8995. 

Polymer Bulletin 42, No.5, May 1999, p.579-86 RHEO-OPTICAL FOURIER TRANSFORM INFRARED SPECTROSCOPY OF DIOL-MODIFIED DIGLYCIDYL ETHER OF BISPHENOL-A EPOXY RESINS Scherzer T... 

Journal of Applied Polymer Science 59, No.9, 28th Feb.1996, p.1417-26 POLYMERISATION KINETICS OF POLYURETHANE AND VINYL ESTER RESIN INTERPENETRATING POLYMER NETWORKS BY USING FOURIER TRANSFORM INFRARED SPECTROSCOPY... 

For many fabric recycling processes such as nylon depolymerization and polymer resin recovery, it is desirable or required to sort the feedstock according to the type of fibers. For carpet, the sorting is according to the type of the face fiber. A melt point indicator is an inexpensive instrument that can identily most fiber types, but it is generally slow and cannot distinguish between nylon 6,6 and polyester. Infrared and Raman spectroscopy are much more effective. Table 6.1 compares the various carpet identification systems. ... 

Gas evolution practically ceases 5-15 min after the beginning of the reaction. However, the process of thermal destruction continues, liquid products of comparatively low molecular weight distilling off from the polymer. In the case of unhardened epoxide resins, the liquid destruction products, according to the data of infrared spectroscopy, represent a mixture of low-molecular fractions of the resin, capable of being converted to the infusible and insoluble state under the influence of hardeners. 

The polymers described in this chapter are industrial-grade materials, and consequently some of the examples may contain additives and/or may be chemically modified. Polymers in various morphological forms may be analyzed, and these include films, fibers, solid pelletized and powdered products, and dissolved/dispersed materials in liquids such as paints and latex products. Also, the same base polymer, such as a styrene-butadiene copolymer, for example, may exist in a rubber, a resin, or a plastic. In general, reference will not be made to the original source of the polymer samples. Because infrared spectroscopy is more widely used than the Raman method, the authors will focus more on the applications of this technique. However, the Raman method, which is complementary to the IR method, does have important and unique applications in the polymer analysis, especially with regard to the determination of the fundamental polymer structure and its... 

Zagorodni AA, Kotova DL, Selemenev VF (2002) Infrared spectroscopy of ion exchange resins chemical deterioration of the resins. React Funct Polym 53 157-171... 

Detailed near-infrared spectra of PET exposed to different relative humidities indicated three different subbands of the first overtone of water at 7080 cm 7010 cm and 6810 cm The comparison with the water spectmm of bulk water suggested that most of the water is only weakly bonded with PET (89). The analysis of difference spectra of dry nylon and nylon exposed to different humidities, indicated that there were distinct populations of hydrogen-bonded water in it (90). Recently, Musto et al. (91) investigated the nature of molecular interactions of water in epoxy resins by means of near-infrared spectroscopy as proposed by Eukuda et al. (89,90). They found three subbands at 7076 cm 6820 cm and 6535 cm evidencing two kinds of water adsorbed in the polymer (mobile water localized in micro vide and water molecules firmly bonded to the network). However, hydroxyl groups of epoxy may complicate the analysis of water content in polymers because they absorb also in the same overtone region as water. 

Kortaberria, G., et al.. Curing of an Epoxy Resin Modified with Poly(Methylmethacrylate) Monitored by Simultaneous Dielectric/Near Infrared Spectroscopies. Europ. Polym, J., 2004.40 129-136. Mijovic, J., et al.. Interplay of Segmental and Normal Mode Dynamics in Polymer Networks Undergoing Chemical Cross-Linking. Epoxy/Amine-Terminated Linear and Stai PPO Eormnlations. Macmmolecules, 2003. 36 4589-4602. 

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