title: Investigations of thiol-modified phenol derivatives for the use in thiol-ene photopolymerizations.
abstract: Thiol-ene photopolymerizations gain a growing interest in academic research. Coatings and dental restoratives are interesting applications for thiol-ene photopolymerizations due to their unique features. In most studies the relative flexible and hydrophilic ester derivative, namely pentaerythritoltetra(3-mercaptopropionate) (PETMP), is investigated as the thiol component. Thus, in the present study we are encouraged to investigate the performance of more hydrophobic ester-free thiol-modified bis- and trisphenol derivatives in thiol-ene photopolymerizations. For this, six different thiol-modified bis- and trisphenol derivatives exhibiting four to six thiol groups are synthesized via the radical addition of thioacetic acid to suitable allyl-modified precursors and subsequent hydrolysis. Compared to PETMP better flexural strength and modulus of elasticity are achievable in thiol-ene photopolymerizations employing 1,3,5-triallyl-1,3,5-triazine-2,4,6-trione (TATATO) as the ene derivative. Especially, after storage in water, the flexural strength and modulus of elasticity is twice as high compared to the PETMP reference system.
authors.affiliation: Heinrich-Heine-University Düsseldorf, Institute of Organic Chemistry and Macromolecular Chemistry, Department of Preparative Polymer Chemistry, Universitätsstraße 1, 40225 Düsseldorf, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Reinelt
authors.affiliation: Heinrich-Heine-University Düsseldorf, Institute of Organic Chemistry and Macromolecular Chemistry, Department of Preparative Polymer Chemistry, Universitätsstraße 1, 40225 Düsseldorf, Germany.
authors.forename: Monir
authors.initials: M
authors.lastname: Tabatabai
authors.affiliation: Ivoclar Vivadent AG, Bendererstrasse 2, 9494 Schaan, Principality of Liechtenstein.
authors.forename: Urs Karl
authors.initials: UK
authors.lastname: Fischer
authors.affiliation: Ivoclar Vivadent AG, Bendererstrasse 2, 9494 Schaan, Principality of Liechtenstein.
authors.forename: Norbert
authors.initials: N
authors.lastname: Moszner
authors.affiliation: Heraeus Kulzer GmbH, Philipp-Reis-Straße 8, 61273 Wehrheim, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Utterodt
authors.affiliation: Heinrich-Heine-University Düsseldorf, Institute of Organic Chemistry and Macromolecular Chemistry, Department of Preparative Polymer Chemistry, Universitätsstraße 1, 40225 Düsseldorf, Germany.
authors.forename: Helmut
authors.initials: H
authors.lastname: Ritter
keywords: composites; crosslinking; dental polymers; high performance polymers; photopolymerization