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001-es BibID:	BIBFORM005398
Első szerző:	Kéki Sándor (polimer kémikus)
Cím:	Atmospheric Pressure Photoionization Mass Spectrometry of Polyisobutylene Derivatives / Sándor Kéki, János Török, Lajos Nagy, Miklós Zsuga
Dátum:	2008
Megjegyzések:	A detailed atmospheric pressure photoionization mass spectrometric (APPI-MS) study on three types of polyisobutylene derivatives is reported. Two of the polyisobutylenes investigated were polyisobutylene with dihydroxy and diolefinic end-groups derived from aromatic moieties [dicumyl chloride, 1,4-bis(2-chloro-2-propyl)benzene], and the third contained no aromatic moieties with a monohydroxy end-group. All three polyisobutylene derivatives (PIBs) had an average molecular weight (Mn) of ?2000 g/mol, with a polydispersity lower than 1.2. The experimental setup allowed the study of the influence of the end-group and the initiator moiety on the APPI-MS properties of these polymers. In the positive ion APPI mode, protonated PIB molecules were formed, but the molecular weights obtained were considerably lower than those expected, indicating fragmentation of the PIB chains. In the negative APPI mode, using solvents such as tetrahydrofuran and toluene as dopants, no signal was obtained. However, in chlorinated solvents, such as CCl4, CHCl3 and CH2Cl2, in the presence of toluene dopant, PIB adducts with chloride ions were formed with relatively high signal intensity. In the case of CH2Cl2, no dopant (toluene) was necessary to generate chlorinated adduct ions, albeit increasing the toluene concentration in the flow increased the PIB signal intensity. The effect of the toluene concentration (at a fixed total flow rate) on PIB signal intensity was thoroughly studied and models that include (i) photoionization of toluene, (ii) formation of chloride ions from the chlorinated solvents by dissociative electron capture, (iii) formation of chlorinated adduct ions and charge recombination reactions between the toluene radical cation, (iv) chloride ions, and (v) chlorinated adduct ions are proposed based on the experimental results.
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban Polyisobutylene APPI-MS mass spectrometry chloride ion attachment
Megjelenés:	Journal of the American Society for Mass Spectrometry. - 19 (2008), p. 656-665. -
További szerzők:	Török János Nagy Lajos (1979-) (vegyész) Zsuga Miklós (1944-) (polimer kémikus)
Internet cím:	DOI elektronikus változat
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