Haftfestigkeit organischer Reste (IV)

Braun, Julius v.; Murjahn, Robert

doi:10.1002/cber.19260590621

Cited by 44 publications

(22 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Undoubtedly, a direct route to polythioethers is the photoinduced polyaddition of AB monomers, that is, α,ω‐alkylene thiols, which was first described in the late 1920s by Braun and Murjahn . Intriguingly, this approach overcomes the inherent disadvantage of an AA/BB monomer approach to obtain high degrees of polymerization due to the high sensitivity in regard to the functional group stoichiometry.…”

Section: Chemistrymentioning

confidence: 99%

Sulfur Chemistry in Polymer and Materials Science

Mutlu

Ceper

et al. 2018

Macromol. Rapid Commun.

254

220

View full text Add to dashboard Cite

The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/marc.201800650. ChemistryBefore moving to the recent advances within the last 5 years in the diverse applications of sulfur chemistry in polymer and Sulfur-Containing PolymersSulfur and its functional groups are major players in an area of exciting research taking place in modern polymer and materials science, both in academia and industry. In fact, manifold sulfur-based reactions that are both exceptionally versatile as well as tremendously useful have been implemented, and further utilized for the design and preparation of polymeric materials that lead to a plethora of applications ranging from medicine to optics and nanotechnology to separation science. Hence, within this review, an overview of strategies and developments used over the last 5 years to reinforce the importance of the sulfur functional group in modern polymer and materials science is presented. In particular, many important references in the primary literature of sulfur chemistry are referred to, including thiol-ene, thiol-yne, thiol-Michael addition, disulfide cross-linking, and thiol-disulfide exchange, among others, by explaining and illustrating the important principles. Last but not least, the grand aim to underpin the importance of sulfur in modern polymer and materials science is achieved by presenting selected examples in diverse fields and postulating the respective potential for real-world applications. he is now a full professor at KIT.sulfur atoms, and tetraphenylethene-bearing di(alkyl bromide) (Scheme 3). The yield of the polymerization was dependent on the di(alkyl bromide) monomer; the longer spacer between the aromatic moiety and the reactive bromide end groups Scheme 1. The discussion henceforth focuses on the synthesis of polymers possessing the depicted sulfur functional groups. Scheme 2.Representative examples of polythioethers prepared via A) the nucleophilic substitution reaction between an electrophilic dihalide with nucleophilic derivatives of dithiols under alkaline conditions; B) the thiol-ene/yne addition reaction between AA and BB type monomers (i.e., dithiols and dienes/diynes); and C) radical or ionic ring-opening of sulfurcontaining strained rings.Scheme 3. The thiol-bromo polymerization of conformationally fixed monomers to provide multifunctional polymers. [19] Macromol. Rapid Commun. 2019, 40, 1800650 Scheme 4. The regioselective selective nucleophilic aromatic substitution between thiol and fluorinated aromatic compounds, the para-fluorothiol reaction (PFTR).Scheme 5. Synthesis of a linear polymer via PFTR-reaction. [21]

show abstract

Section: Chemistrymentioning

confidence: 99%

Sulfur Chemistry in Polymer and Materials Science

Mutlu

Ceper

et al. 2018

Macromol. Rapid Commun.

254

220

View full text Add to dashboard Cite

show abstract

“…Thiol‐ene coupling reactions are not new chemistry, but have been rather extensively studied over the last century,24–26 and were described as early as 1926 by Braun and Murjahn 27. While thiol‐ene polymerizations are in use for the formation of networks22, 28 or for the purpose of controlling molecular weight in radical polymerizations, thiol‐ene coupling is more recently also referred to as a click reaction 29.…”

Section: Introductionmentioning

confidence: 99%

Limitations of radical thiol‐ene reactions for polymer–polymer conjugation

Koo

Stamenović

Ramaswamy

et al. 2010

J. Polym. Sci. A Polym. Chem.

238

229

View full text Add to dashboard Cite

In the current work, we report our findings on the use of radical thiol-ene chemistry for polymerpolymer conjugation. The manuscript combines the results from the Preparative Macromolecular Chemistry group from Karlsruhe Institute of Technology (KIT) and the Polymer Chemistry Research group from Ghent University (UGent), which allowed for an investigation over a very broad range of reaction conditions. In particular, thermal and UV initiation methods for the 2 radical thiol-ene process were compared. In the KIT group, the process was studied as a tool for the synthesis of star polymers by coupling multi-functional thiol core molecules with poly(nbutyl acrylate) macromonomers (MM), employing thermally decomposing initiators. The product purity and thus reaction efficiency was assessed via electrospray ionization mass spectrometry. Although the reactions with 10 or 5 equivalents of thiol with respect to macromonomer were successful, the coupling reaction with a one-to-one ratio of MM to thiol yielded only a fraction of the targeted product, besides a number of side products. A systematic parameter study such as a variation of the concentration and nature of the initiator and the influence of thiol to ene ratio was carried out for a one-to-one ratio of MM to thiol content.Further experiments with poly(styrene) and poly(isobornyl acrylate) containing a vinylic end group confirmed that thermal thiol-ene conjugation is far from quantitative in terms of achieving macromolecular star formation. In parallel, the UGent group has been focusing on photo-initiated thiol-ene chemistry for the synthesis of functional polymers on the one hand and block copolymers consisting of poly(styrene) (PS) and poly(vinyl acetate) (PVAc) on the other hand.Various functionalization reactions showed an overall efficient thiol-ene process for conjugation reactions of polymers with low molecular weight compounds (~90% coupling yield). However, while SEC and FT-IR analysis of the conjugated PS-PVAc products indicated qualitative evidence for a successful polymer-polymer conjugation, 1 H NMR and elemental analysis revealed a low conjugation efficiency of about 23% for a thiol-to-ene ratio equal to one. Blank reactions using typical thiol-ene conditions indicated that bimolecular termination reactions 3 occur as competitive side reactions explaining why a molecular weight increase is observed even though the thiol-ene reaction was not successful. The extensive study of both research groups indicates that radical thiol-ene chemistry should not be proposed as a straightforward conjugation tool for polymer-polymer conjugation reactions. Head-to-head coupling is a major reaction pathway, which interrupts the propagation cycle of the thiol-ene process.

show abstract

“…1 H NMR spectra were recorded on a Varian Gemini 200 spectrometer at 200 MHz with TMS as internal reference. The FT-IR spectra were recorded on a Mattson 1000 FT-IR spectrometer.…”

Section: Methodsmentioning

confidence: 99%

“…The first example of this type of polymerization, the self-polymerization of allylthiol, was reported in 1926 1) . Since then, many polymers have been prepared based on this principle.…”

Section: Introductionmentioning

confidence: 98%