MALDI-TOF Characterization of Highly Cross-Linked, Degradable Polymer Networks

Burkoth, Amy K.; Anseth, Kristi S.

doi:10.1021/ma9814651

Cited by 58 publications

(42 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In contrast, few MS studies have been reported for PMAA and most of them focused on the analysis of volatile thermal degradation products of the polymer [33,34]. Intact PMAA oligomer ions could be produced by matrix assisted laser desorption/ionization (MALDI) [35][36][37][38]. Although mass averages from these MS data were often biased to low molecular weight and produced with poor signal-to-noise ratios, information regarding absolute masses of each individual macromolecular species was available, allowing monomer and end-group masses to be confirmed.…”

mentioning

confidence: 99%

Tandem mass spectrometry of poly(methacrylic acid) oligomers produced by negative mode electrospray ionization

Giordanengo

Viel

Allard-Breton

et al. 2009

J. Am. Soc. Mass Spectrom.

View full text Add to dashboard Cite

Dissociation of small poly(methyl acrylic acid) (PMAA) anions produced by electrospray was characterized by tandem mass spectrometry. Upon collisional activation, singly, and doubly deprotonated PMAA oligomers were shown to fragment via two major reactions, dehydration and decarboxylation. The elimination of a water molecule would occur between two consecutive acid groups in a charged-remote mechanism, giving rise to cyclic anhydrides, and was shown to proceed as many times as pairs of neutral pendant groups were available. As a result, the number of dehydration steps, together with the abundance of the fragment ions produced after the release of all water molecules, revealed the polymerization degree of the molecule in the particular case of doubly charged oligomers. For singly deprotonated molecules, the exact number of MAA units could be reached from the number of carbon dioxide molecules successively eliminated from the fully dehydrated precursor ions. In contrast to dehydration, decarboxylation reactions would proceed via a charge-induced mechanism. The proposed dissociation mechanisms are consistent with results commonly reported in thermal degradation studies of poly(acrylic acid) resins and were supported by accurate mass measurements. These fragmentation rules were successfully applied to characterize a polymeric impurity detected in the tested PMAA sample. (J Am Soc Mass

show abstract

mentioning

confidence: 99%

Tandem mass spectrometry of poly(methacrylic acid) oligomers produced by negative mode electrospray ionization

Giordanengo

Viel

Allard-Breton

et al. 2009

J. Am. Soc. Mass Spectrom.

View full text Add to dashboard Cite

show abstract

“…The analytical protocols used in positive ion mode are 2,5-dihydroxybenzoic acid (DHB) matrix in methanol [4] or DHB and sodium trifluoroacetate in acetone [5]. Sinapinic acid in methanol (MeOH) or water (H 2 O) has been used in negative ion mode [6]. Consistent throughout these data are very poor signal-to-noise ratios and non-isotopic resolution of the observed species.…”

mentioning

confidence: 99%

Strategies for the analysis of poly(methacrylic acid) by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

Wyatt

Schaeffer

Tan

et al. 2007

J. Am. Soc. Mass Spectrom.

View full text Add to dashboard Cite

We evaluated several aqueous-based sample preparation protocols for the analysis of poly(methacrylic acid) (PMAA) by matrix-assisted laser desorption/ionization time-offlight mass spectrometry (MALDI-TOFMS). The sample contained a pentaerythritol tetra(3-mercaptopropionate) end-group, and was characterized in positive and negative ion modes using 2,5-dihydroxybenzoic acid (DHB) and 2,4,6-trihydroxyacetophenone (THAP) matrices. The major series observed were the [M ϩ Na] ϩ species, in positive ion mode, and the [M Ϫ H] Ϫ species, in negative ion mode. The performance of DHB and THAP matrices was comparable in positive ion mode, but THAP outperformed DHB in negative ion mode. The use of ion-exchange beads (IXB) benefited the analysis, while the addition of sodium acetate (NaOAc A lthough matrix-assisted laser desorption/ ionization time-of-flight mass spectrometry (MALDI-TOFMS) has been utilized predominately within the life sciences, there has been considerable use of this technique for the characterization of synthetic polymers. The large body of work in this area has been the subject of several reviews [1][2][3]. However, there are few examples of the characterization of poly(methacrylic acid) (PMAA) homopolymers by MALDI-TOFMS in the literature. The analytical protocols used in positive ion mode are 2,5-dihydroxybenzoic acid (DHB) matrix in methanol [4] or DHB and sodium trifluoroacetate in acetone [5]. Sinapinic acid in methanol (MeOH) or water (H 2 O) has been used in negative ion mode [6]. Consistent throughout these data are very poor signal-to-noise ratios and non-isotopic resolution of the observed species.The current investigation is concerned with the analysis of a low molecular weight PMAA sample containing a pentaerythritol tetra(3-mercaptopropionate) end group (PTMP-PMAA), shown in Figure 1, by MALDI-TOFMS. This polymer and similar ligands have been used as a ligand in the size-controlled synthesis of gold nanoparticles, which are only soluble in water [7,8]. The goal of the study was to establish aqueous-based sample preparation protocols that would provide data with improved signal-to-noise ratios and resolution compared with existing methods. These protocols could subsequently be used for the characterization of the PMAA-coated gold nanoparticles [8]. ExperimentalDHB and 2,4,6-trihydroxyacetophenone (THAP) matrices, and trifluoroacetic acid (TFA), were purchased from Fluka (Dorset, UK). Dowex 50W-X8, 200 m, ion-exchange beads (IXB), di-ammonium hydrogen citrate (DAC), sodium acetate (NaOAc), and ammonium acetate were purchased from Sigma-Aldrich (Dorset, UK). IXB were loaded with NH 4 ϩ ions as reported previously [9]. HPLC grade acetonitrile (MeCN) and MeOH, both purchased from Fisher Scientific (Loughborough, UK), and Milli-Q H 2 O (Watford, UK) were used where appropriate. PTMP-PMAA (M n ϭ 1900 g mol Ϫ1 and M w ϭ 2240 g mol Ϫ1 by GPC) was synthesized as reported elsewhere [8].DHB and THAP matrix solutions were made to a concentration of 10 mg mL Ϫ1 in 1:1 (vol/vol) H 2 O/ MeCN. DHB solution wa...

show abstract

“…Anseth et al investigated the volume shrinkage, conversion, and kinetic chain length in the cross-linked network structure by means of kinetic measurement, matrix assisted laser desoprption/ionization time-of-flight mass spectroscopy (MALDI-TOF MS), and gel permeation chromatography [2][3][4]. Their results indicated the existence of diffusioncontrolled kinetics which is affected by the cross-linked network.…”

Section: Introductionmentioning

confidence: 99%

Comparison of Network Structure Photopolymerized under UV-LED and High-Pressure Mercury Lamp with Different Photoinitiators

Taki

Taguchi

Hayashi

et al. 2017

J. Photopol. Sci. Technol.

View full text Add to dashboard Cite

UV-curable resin of multifunctional monomers is believed to form a cross-linked network structure. However, the nature of this network is difficult to analyze. In this study, a kinetic approach was applied to compare the network structures of photopolymerized diurethane dimethacrylate cured by different light sources and photoinitiators. The conversion after UV irradiation was monitored to calculate the rate coefficients of propagation and termination (k p and k t , respectively) under varying irradiation times and at constant UV intensity and temperature. The values of k p and k t were compared for different UV light sources (a 365-nm peak UV-LED and a high-pressure mercury lamp) and different photoinitiators (1-hydroxycyclohexylphenylketone (HCAP) and 2,4,6-trimethylbenzoylphenyl phosphinate (TPO)). The results indicate that the network structure formed under different light sources with the same photoinitiator could be scaled, namely that the formed cross-linked network structures could be superimposed on top of each other by linear expansion or reduction. The reason is that the light sources only differ in the rate of photon delivery, while the photons are identical to each other in terms of chemical reactivity. In contrast, the network structures formed with different photoinitiators could not be scaled, since the photoinitiators differ in their quantum yield, kinetic constants, affinity, and molecular size. These factors could affect the network structure. Although the kinetic analysis in this study only provides very limited information about the network structure, we experimentally confirmed that the network structure depends on both the UV light source and photoinitiator.

show abstract

MALDI-TOF Characterization of Highly Cross-Linked, Degradable Polymer Networks

Cited by 58 publications

References 27 publications

Tandem mass spectrometry of poly(methacrylic acid) oligomers produced by negative mode electrospray ionization

Tandem mass spectrometry of poly(methacrylic acid) oligomers produced by negative mode electrospray ionization

Strategies for the analysis of poly(methacrylic acid) by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

Comparison of Network Structure Photopolymerized under UV-LED and High-Pressure Mercury Lamp with Different Photoinitiators

Contact Info

Product

Resources

About