Tris(trimethylsilyl)silane as a co-initiator for dental adhesive: Photo-polymerization kinetics and dynamic mechanical property

Abstract

Objectives The purpose of this study was to evaluate the polymerization behavior of a model dentin adhesive with tris(trimethylsilyl)silane (TTMSS) as a co-initiator, and to investigate the polymerization kinetics and mechanical properties of copolymers in dry and wet conditions. Methods A co-monomer mixture based on HEMA/BisGMA (45/55, w/w) was used as a model dentin adhesive. The photoinitiator system included camphorquinone (CQ) as the photosensitizer and the co-initiator was ethyl-4-(dimethylamino) benzoate (EDMAB) or TTMSS. Iodonium salt, diphenyliodonium hexafluorophosphate (DPIHP) serving as a catalyst, was selectively added into the adhesive formulations. The control and the experimental formulations were characterized with regard to the degree of conversion (DC) and dynamic mechanical properties under dry and wet conditions. Results In two-component photoinitiator system (CQ/TTMSS), with an increase of TTMSS concentration, the polymerization rate and DC of C═C double bond increased, and showed a dependence on the irradiation time and curing light intensity. The copolymers that contained the three-component photoinitiator system (CQ/TTMSS/DPIHP) showed similar dynamic mechanical properties, under both dry and wet conditions, to the EDMAB-containing system. Significance The DC of formulations using TTMSS as co-initiator showed a strong dependence on irradiation time. With the addition of TTMSS, the maximum polymerization rate can be adjusted and the network structure became more homogenous. The results indicated that the TTMSS could be used as a substitute for amine-type co-initiator in visible-light induced free radical polymerization of methacrylate-based dentin adhesives.

Influence of Al2O3 Nanoparticle Addition on a UV Cured Polyacrylate for 3D Inkjet Printing

“…The same behavior can be seen for the 16 nm sized fillers, where the increase from 1.22 to 1.95 vol % leads to a local maximum of the tensile properties to shrink again for 3.8 vol %. On the other hand, the ligand MPS contributed not only to the stability of the nanoparticles in the organic matrix but, as a silane, it is known to act as a co-photoinitiator [21,31]. According to literature, about 1.49 mg/m 2 is needed to form a closed organic shell [32,33,34,35,36].…”

Probing the neutralization behavior of zwitterionic monomer-containing dental adhesive

“…The dynamic mechanical properties of methacrylate-based dental adhesives have been reported by our group [38–41]. The frequency that was used to measure the storage modulus is 1 Hz with an amplitude of 15 μm and a preload of 0.01 N [38, 40]. In the dry condition, the storage modulus is measured from 10 to 150 °C with a ramping rate of 3 °C min −1 .…”

Sole‐Component Visible Macrophotoinitiators with Si‐H: Decreased Oxygen Inhibition and Modified Cured Polymer Materials

“…The yield of alkylamino radical was more rapidly than silyl radicals. [43] It perhaps that there was almost no silyl radical yielded; and the photolysis in TXÀ A/PMHS was almost the same as that in TXÀ A system at the first 1.0 h. Under photolytic conditions, the accumulated alkylamino radical (R⋅) makes radical transfer to form silyl radical (Scheme 2, C) or PI* abstracts the hydrogen from the SiÀ H to give a silyl radical (Scheme 2, A). Ketyl radicals of TX will be deactivated by radical-radical process.…”