Poly mass spectrum

Examination of the mass spectrum of P2VPY taken during the maximum decomposition rate reveals the major decomposition products as methylpyridine (93 a.m.u.), protonated vinyl pyridine (106 a.m.u.), and protonated dimer (211 a.m.u.) with ion ratios 74 100 59 respectively. Trimeric and tetrameric protonated species (316 and 421 a.m.u.) are also observed but in relatively small amounts. Protonated ions, rather than the simple monomers and dimers observed for the decomposition of poly(styrene) by MS11, may be created by a mechanism similar to that reported for the decomposition of 2-(4-heptyl)pyridine12 in the mass spectrometer. 

As an example of the form of the information that may be derived from a pyrolysis-MS, Figure 26 [69] shows the structure of the polycarbonate (PC) and the EI-MS spectra of pyrolysis compounds obtained by DPMS of poly(bisphenol-A-carbonate) at three different probe temperatures corresponding to the three TIC (total ion current) maxima shown in Figure 27(b) Figure 27 compares the MS-TIC curve with those obtained from thermogravimetry. (The TIC trace is the sum of the relative abundances of all the ions in each mass spectrum plotted against the time (or number of scans) in a data collection sequence [70].)... 

Fig. 9.30 a) Normalized MALDI TOF mass spectrum of all fractions (taken after 2 h to 72 h of polymerization time) of poly(2-phenyl-2-oxazoline) freed by dissolving the gold core with NaCN solution and collection of the polymer. The calculated mass of the monomer unit (147.17) is in good agreement with the spacing of the mass signals (AM = 146.93) of the most prominent peaks. Based on ear-... 

Fig. 2.12. MALDI mass spectrum of a side-chain substituted poly(p-phenylene). The splitting of the mass peaks of the respective -mers is caused by the different combinations of end groups, i.e., H,H, H,Br, or Br,Br...

From the field desorption mass spectra of standard samples, a table for identification of poly(oxyethylene) alkylphenyl ethers and determination of the degree of polymerisation of ethylene oxide was constructed as shown in Table 6.1 n is the number of alkyl carbon atoms and m is the degree of polymerisation of ethylene oxide. When the field desorption mass spectrum having a peak pattern with the difference of 44m/z was obtained such as the peaks at 484, 528, 572, 616 and 660m/z, Table 6.1 would show that those peaks are due to poly(oxyethylene) nonylphenyl ethers with the degree of polymerisation of 6-10 of ethylene oxide. Table 6.2 also shows the identification of poly(oxyethylene) dialkylphenyl ethers and determination of the degree of polymerisation of ethylene oxide based on calculations of the molecular weight. 

An ESI mass spectrum of a mixture of 1 1 d(pT)13 d(pA)14 with the gene V protein (Fig. 13a) shows the existence of a double-stranded dimer and of a complex between the protein and a single d(pT)13 oligonucleotide. Complexes of the protein with the dsDNA, or with d(pA)14 do not appear in the spectrum. This clearly points to the preference for binding ssDNA over dsDNA and poly(dT) over polyfdA). When the mixture of d(pT)13 d(pT)15 ... 

Figure 11. Laser desorption electron-impact mass spectrum of poly-(dimethylsilane) under low (a) and high (b) resolution.

Figure 2. Electrospray ionization mass spectrum of octylphenoxy-poly(ethoxy) ethanol. Inset is the total ion chromatogram. Conditions are given in Experimental Details.

Similar to the study of other pyrolysates, the analysis of the pyrolysate of poly(butyl acrylate) leads to some components that are difficult to identify. For example, the mass spectrum of dibutyl 2-methylenepentane-1,5-dioate (dimer of butyl acrylate) is not available in common mass spectral libraries, and it is shown in Figure 6.7.9. 

The identification of some of the peaks in the pyrograms of poly[(o-cresyl glycidyl ether)-co-formaldehyde] was done only tentatively. For example, the mass spectrum of [(2-... 

Figure 11.1.5. Mass spectrum for the peak eluting at 111.57 min. in the pyrogram of poly(hexamethylene carbonate), possibly of 6-hydroxyhexyl carbonate (MW= 162).

FIGURE 23 Positive ion ESP mass spectrum of a poly(ethylene glycol) mixture. 

Fig. 3.7. Data (time) domain signal produced by 9.4-Tesla Fourier-transform ion cyclotron resonance mass spectrometer (left), and frequency domain signal (i.e. mass spectrum) after fast Fourier transformation and frequency-to-mass calculation (right). The sample was a mixture of poly(ethylene) glycol polymers used for internal calibration.

The El mass spectrum that results is comprised of the molecular ion and all fragment ions the degree of fragmentation can be reduced by lowering tire electron energy to <15 eV. Figure 1.1 shows the El mass spectra of the photolysis products of poly(ethylene) and poly(propylene). Each spectrum shows the molecular ions of several hydrocarbon subunits (m/z values... 

Field desorption mass spectrum of poly(styrene) 12500. (Reprinted from Ref. 14 with permission... 

TSP mass spectrum of an equimolar mixture of four poly(ethylene glycols), viz. PEG 300, 600, 1000, and 1450 the m/z range 300-700 is displayed. The major ions correspond to [M + NH4] adducts. (Reprinted from Ref. 31 with permission of the American Chemical Society)... 

Figure 2.22a reports the DCI mass spectrum of a microbial copolyester, poly()3-hydroxybutyrate-co-15% )3-hydrox5rvalerate)(PFlB/HV). The relative intensities of several series of oligomers in the spectrum, from dimers to hexamers, are compared with theoretical intensities (Figure 2.22b). Each series...

Poly(2,2,4-trimethyl-l,2-dihydroquinoline), an oligomeric antioxidant for rubber, is a typical example for this ionization method. Figure 6.3 shows the FD mass spectrum of a poly-TMDQ sample. Molecular ions for "normal" oligomers (M = 173n) are observed, along with minor peaks due to impurities (with differing end-groups) from the synthesis. 

Positive ions FAB mass spectrum of poly(resordnol phathalate) (polyester II). (Reprinted with permission from Ref. 55, Copyright 1994, American Chemical Society.)... 

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