Spectra butyl rubber

Figure 10 shows a spectrum of butyl rubber gum stock obtained on the solid at 80°C using normal pulsed FT techniques. Clearly it could be identified as a component in fabricated materials by direct nmr spectral analysis. Figure 11 shows spectra obtained from various portions of typical rubber products. These samples were cut from the rubber product, placed in an nmr tube without solvent, and spectra obtained at an elevated temperature. The data show how polyisoprene, a polyisoprene/polybutadiene blend and a polyisobutylene/polyisoprene/polybutadiene rubber blend are quickly identified in the materials. Figure 11a shows processing oil was present, and which was confirmed by solvent extraction. 

Figure 12. Example of an FTIR spectrum for butyl rubber.

Figure 11.2 H-NMR spectra of butyl rubber, (a) olefinic region, (b) full spectrum after epoxidation, observed at 500MHz [14]...

Figure 11.14 -NMR spectrum of (a) commercial butyl rubber and (b) polyisobutylene, observed at 500 MHz [84]...

Natural rubber is compatible with paraffinic, naphthenic, and aromatic oil plasticizers. Only butyl rubber has similar compatibility. All other synthetic rubbers are compatible with a limited spectrum of mineral oils. These are recent applications ... 

The example shown is that of a carbon-filled butyl rubber. Direct internal reflection application yielded the spectrum in Figure 14.22a. The effect of the carhon hlack can he seen and only weak butyl rubber bands are observed. Following elimination of the carbon, Figure 14.22h was obtained. Certainly this is a much easier spectrum to work with for identification. Other types of carhon-filled rubbers and polyethylene have been successfully treated with this technique. 

Fig. 14.22 (a) Infrared spectrum of carbon-filled butyl rubber by internal refiection b) transmission... 

Fig. 6.14. H-NMR spectrum of butyl rubber at 250 MHz in CDCI3. (Reproduced from Ref. [40]. 1985 American Chemical Society.)...

Fig. 6.15. High-field region of the H-NMR spectrum of butyl rubber (at 250 MHz in CDCI3). Spectrum a is of commercial butyl rubber, spectrum b is of specifically deuterated butyl rubber, and c is the a — b difference spectrum. The signal at 1.65 results from the E isomer, and the weak signal at 1.70 results from the Z isomer. (Reproduced from Ref. [40]. 1985 American Chemical Society.)...

FIGU RE 14.6 Viscoelastic spectrum for butyl rubber filled with 40 phr carbon black. (From Snowdon, J. C., Vibration and Shock in Damped Mechanical Systems, 1990. Reprinted with permission of John Wiley Sons, Inc.)... 

The system Cl-buty 1-natural rubber (or cw-polyisoprene) could not be resolved by differential solvent techniques because the polymeric solubility parameters were too similar. At one end of the spectrum—i.e., with styrene at — 25 °C—natural rubber could be highly swollen while restricting the chlorobutyl swell, but the reverse was not possible, as indicated by the swelling volumes in the trimethylpentane. As displayed in Table II, attempts to use a highly symmetrically branched hydrocarbon with a very low solubility parameter, served only to reduce both the swelling of natural rubber and chlorobutyl. (Neopentane is a gas above 10°C and a solid below — 20°C). Therefore, for this report the use of differential solvents in the study of interfacial bonding in blends was limited to systems of Cl-butyl and cw-polybutadiene or SBR. 

Under the heading acrylic elastomer the plastic literature has included a broad spectrum of carboxy-modified rubbers that have as a minor portion of the comonomers acrylic acid and/or its derivatives. However, in more recent usage the term acrylic elastomer is used to designate these rubbery products that contain a predominant amount of an acrylic ester, such as ethyl acrylate or butyl acrylate in the polymer chain. Fluoroacrylate elastomers are based on plastics prepared from the acrylic acid ester-dihydroperfluoro alcohols. 

Herve-Bazin B, Gradiski D, Duprat P, Marignac B, Foussereau J, Cavelier C, Bieber P (1977) Occupational eczema from JV-isopropyl-N -phenylpara-phenylenediamine (IPPD) and iSf-dimethyl-1,3 butyl-2V -phenylparaphenylenediamine (DMPPD) in tyres. Contact Dermatitis 3 1-15 Von Hintzenstern J, Heese A, Koch HU, Peters KP, Hornstein OP (1991) Frequency, spectrum and occupational relevance of type IV allergies to rubber chemicals. Contact Dermatitis 24 244-252... 

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