Thermal and Photochemical Crosslinking of Hyperbranched Polyphenylene With Organic Azides

Pötzsch, Robert; Voit, Brigitte

doi:10.1002/marc.201100795

Cited by 20 publications

(16 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Our initial interest in TYC was driven by the challenge of developing new cross‐linking/functionalization strategies for hyperbranched polyphenylene (hb‐PPh) and reactive coatings . Specifically, the question of whether DPA (present as end groups in hb‐PPh) would be able to react with a thiol due to steric and electronic demands and what is the regiochemical outcome of the reaction, were of primary interest.…”

Section: Resultsmentioning

confidence: 99%

Radical Thiol‐yne Chemistry on Diphenylacetylene: Selective and Quantitative Addition Enabling the Synthesis of Hyperbranched Poly(vinyl sulfide)s

Pötzsch

Komber

Stahl

et al. 2013

Macromol. Rapid Commun.

Self Cite

View full text Add to dashboard Cite

A powerful variation of traditional radical thiol-yne reaction with diphenylacetylene (DPA)-based starting materials leading to the quantitative and selective formation of the corresponding vinyl sulfides is reported. A variety of different thiols are shown to undergo reaction with DPA and the influence of their structure on reactivity is studied. The results obtained from the model reactions are then used to guide the efficient synthesis of hyperbranched poly(vinyl sulfide) (hb-PVS) systems by employing a dithiol and a trialkyne in an A2 + B3 approach. The polymers obtained show excellent solubility in common organic solvents and exhibit high refractive indices (e.g., 1.70 at 589 nm). The combined ease of processability and potential for cross-linking make these materials very interesting for applications, such as coatings for optical devices. The selective mono-addition thiol-yne reaction on DPA serves not only as a synthetic method for the preparation of PVS but could also be applied to the general modification of acetylene-containing materials.

show abstract

Section: Resultsmentioning

confidence: 99%

Radical Thiol‐yne Chemistry on Diphenylacetylene: Selective and Quantitative Addition Enabling the Synthesis of Hyperbranched Poly(vinyl sulfide)s

Pötzsch

Komber

Stahl

et al. 2013

Macromol. Rapid Commun.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Again, high temperatures for curing, such as above 200 C, should be avoided because of potential degradation of some active substances. In this regard, a small molecule, namely 1,3,5-tris (azidomethyl)benzene (TAMB), was prepared by Pötzsch and Voit [233] and successfully used to crosslink the hb-PPh matrix both thermally and photochemically. The mechanisms of these two crosslinking reactions were different; in thermal curing, triazole units were formed between the acetylene groups of hb-PPh and the azide group of the crosslinker in a 1,3-dipolar cycloaddition reaction.…”

Section: Hyperbranched Polyphenylenesmentioning

confidence: 99%

Aromatic Hyperbranched Polymers: Synthesis and Application

Ghosh

Banerjee

Voit

2014

Porous Carbons – Hyperbranched Polymers – Polymer Solvation

Self Cite

View full text Add to dashboard Cite

Hyperbranched (hb) polymers have been receiving increasing attention because of their unique architecture that results in an interesting set of unusual chemical and physical properties. Over the past decade quite a number of excellent reviews on hb polymers have been published by different research groups, covering various aspects of this class of polymers. This review will highlight the work on aromatic hb polymers of the last decade, emphasizing general synthetic strategies and recent development of alternative synthetic strategies, and discussing various aspects of hb polymers to demonstrate their wide range of applications.

show abstract

“…One of the disadvantages of this system is the limited shelf life time of the mixtures which leads due to the high reactivity of the azide group with the alkyne moiety to a spontaneous crosslinking. [25][26][27][28] The same polymers as above with only the azide groups have been utilized as photoresists in high resolution lithography. 29,30 In this contribution the chemistry of azide-functionalized copolymers 30 has been adapted to synthesize random copolymers for thin dielectrics for organic FETs which do not show the above addressed problems and are easy to process.…”

Section: Introductionmentioning

confidence: 99%

Cross-linkable random copolymers as dielectrics for low-voltage organic field-effect transistors

et al. 2015

View full text Add to dashboard Cite

A large number of cross-linkable dielectrics with good dielectric properties have been reported; however, all of them suffer from disadvantages like uncontrolled pre-crosslinking, necessity of high process temperatures and the need for an additional cross-linking compound. In this contribution, two new poly(methyl methacrylate) polymers are introduced which can be cross-linked due to the attached benzyl azide (N3) monomer units making the addition of hardeners or initiators obsolete. The synthesis of the copolymers as well as their successful characterization and usage as gate dielectrics for organic field-effect transistors is demonstrated. The investigated polymers have been labeled PAZ 12 and PAZ 14 according to their azide content in mol%. The additional building blocks of the polymers are methyl methacrylate for PAZ 12 and methyl methacrylate and styrene monomer units in about an equal ratio for PAZ 14. Spin-coated thin films were cross-linked by a thermal treatment at 110 °C followed by an UV exposure at a wavelength of 254 nm yielding insoluble, smooth and electrically dense polymeric networks. Optimal cross-linking parameters were obtained using infrared spectroscopy to follow the N3 vibrational mode. Its disappearance confirms a complete cross-linking reaction, and thus fully reacted azide groups facilitate the analytics. The dielectric properties of the cross-linked thin films have been studied by impedance spectroscopy. The application of double layer dielectrics results in lower dielectric losses and lower leakage currents in the subsequently produced pentacene-based field-effect transistors. These devices operate at voltages below −6 V and show hysteresis-free current–voltage characteristics with hole mobilities up to 0.16 cm2 V−1 s−1. PAZ 12 appears to be superior to PAZ 14 due to a lower total layer thickness of down to 92 nm still providing good insulation in the transistor presumably related to a lower free volume that arises in the cross-linked network of the two-component containing copolymer PAZ 12

show abstract

Thermal and Photochemical Crosslinking of Hyperbranched Polyphenylene With Organic Azides

Cited by 20 publications

References 32 publications

Radical Thiol‐yne Chemistry on Diphenylacetylene: Selective and Quantitative Addition Enabling the Synthesis of Hyperbranched Poly(vinyl sulfide)s

Radical Thiol‐yne Chemistry on Diphenylacetylene: Selective and Quantitative Addition Enabling the Synthesis of Hyperbranched Poly(vinyl sulfide)s

Aromatic Hyperbranched Polymers: Synthesis and Application

Cross-linkable random copolymers as dielectrics for low-voltage organic field-effect transistors

Contact Info

Product

Resources

About