Spectra resins

The amino add analysis of all peptide chains on the resins indicated a ratio of Pro Val 6.6 6.0 (calcd. 6 6). The peptides were then cleaved from the resin with 30% HBr in acetic acid and chromatogra phed on sephadex LH-20 in 0.001 M HCl. 335 mg dodecapeptide was isolated. Hydrolysis followed by quantitative amino acid analysis gave a ratio of Pro Val - 6.0 5.6 (calcd. 6 6). Cycll2ation in DMF with Woodward s reagent K (see scheme below) yielded after purification 138 mg of needles of the desired cyc-lododecapeptide with one equiv of acetic add. The compound yielded a yellow adduct with potassium picrate, and here an analytically more acceptable ratio Pro Val of 1.03 1.00 (calcd. 1 1) was found. The mass spectrum contained a molecular ion peak. No other spectral measurements (lack of ORD, NMR) have been reported. For a thirty-six step synthesis in which each step may cause side-reaaions the characterization of the final product should, of course, be more elaborate. 

Palmitic acid, structure of, 1062 Palmitoleic acid, structure of, 1062 PAM resin, solid-phase peptide synthesis and, 1037 Para (m), 519 Paraffin, 91 Parallel synthesis, 586 Parent peak (mass spectrum), 410 Partial charge, 36 Pasteur, Louis, 297, 307... 

Polyethylene separators offer the best balanced property spectrum excellent mechanical and chemical stability as well as good values for acid availability and electrical resistance have established their breakthrough to be the leading traction battery separator. Rubber separators, phenolic resin-resorcinol separators, and mi-croporous PVC separators are more difficult to handle than polyethylene separators their lack of flexibility does not allow folding into sleeves or use in a meandering assembly in addition they are more expensive. 

Epoxies Powder, one and two-part liquids and paste Many types of resins available, providing wide spectrum of properties. Easy to compound. Low shrinkage and excellent dimensional stability. Good to excellent adhesion. May be cast or molded. Coatings, sealants, adhesives, solderless PC boards. 

While the control resins were deep red in color due to the presence of soluble porphyrin complexes, the methacrylate resins obtained after removal of the polyethylene-supported catalysts varied from light yellow to nearly water-white (APHA < 25). UV-Vis spectrophotometric analysis of the yellow resins indicated an absorption signal for the cobalt porphyrin complex Soret band (wavelength of cobalt(ll) porphyrin species appears at -415 nm free porphyrin ligand is formd at -423 tun). Resin samples that visttally appear as water-white show little or no porphyrin species present in the spectrum. Measured catalyst activity and PDl of the polyethylene-supported porphyrin complexes are in the expected range for soluble porphyrin CCT catalysts (PDl = M /Mn - 1.2- 2.0)." The screening resrrlts clearly... 

We have studied demulsifier association by the electron spin resonance (ESR) technique. The spin label is covalently attached (Figure 5a) to the demulsifier. Normally, the ESR spectrum of a freely tumbling nitroxyl radical consists of three sharp peaks (Figure 5b). However, the spectrum for a tagged ethoxylated nonyl phenol resin (Figure 6a or 6b) shows only a single broad peak. 

The FTIR spectrum for the dried paint resin does have a reasonable match score to and feature bands characteristic of an alkyd resin [5]. Due to the presence of fillers though, the spectral analysis did not allow for a high-quality match to be obtained. Removal of the fillers and subsequent FTIR analysis would provide the best spectroscopic result for the identification of the alkyd type and provide a better comparison to such as the reference vinyl toluene-modified alkyd. 

A proton decoupled 13C NMR spectrum of the resin-peptide sample swollen in methylene chloride is shown in Figure A. The spectrum obtained in DMF is quite similar. The strong line at 175 ppm is from the lie carbonyl, and the six intense resonances between 60 and 10 ppm are due, in order of increasing field to the... 

Figures 3.4 3.6 report the average mass spectra obtained, respectively, for frankincense resin, mastic resin and birch bark tar [16]. Moreover, in each spectrum the main ion and ion radical fragments are assigned, and for each material the main molecular markers are shown.

Figure 3.4 Mass spectrum of frankincense resin obtained by DE MS...

Figure 3.17 DE mass spectrum of the resinous material collected from the Roman amphora recovered from a waterlogged archaeological site in Liguria (Italy) [18]...

Figure 5.13 GALDI mass spectrum of aloe resin (from THF solution). The two doublets correspond to mono and diglucosides of aloe emodin and their oxidation and reduction products, respectively (see Table 5.5)...

Table 5.5 Prominent peaks in the mass spectrum of aloe resin (see Figure 5.13), interpretation following the literature. The dyes are not detected as sodium adducts but as radical cations formed by direct absorption and ionisation of the laser energy...

Several historic wax samples were analysed successfully with GALDI-MS. It was found that a group of eighteen white seals from medieval documents (thirteenth to fourteenth century) from the archive of the Canton of Lucerne (Switzerland) all mainly consisted of beeswax. For example, the mass spectrum of a white seal from 1377 (inventory no. URK636/12663) is shown in Figure 5.14b. The typical pattern of beeswax, as described for the reference sample, can be clearly recognised. An additional peak at m/z 303 may be caused by abietic acid in the form of the molecule cation (C2oH3o02, MW 302), as found for rosin (see Section 5.3.2). This hints at the use of a diterpenoid resin, which was a common hardener for beeswax. A more detailed discussion of the composition of medieval white wax seals has been published elsewhere [57]. 

---