Recent developments in photoinitiators

Rutsch, W.; Dietliker, Kurt; Leppard, David G.; Köhler, Moritz; Misev, L.; Kolczak, Urszula; Rist, G.

doi:10.1016/0300-9440(95)00539-0

Cited by 116 publications

(95 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A characteristic of this molecule, like many other photoinitiators, is that it has the capability to "photobleach" after reacting. 12 In this process, the chemical structure of CQ is changed to that of a pinocol, 13 which is white but still has significant absorption in the UV range. Thus, as CQ is used, it has the potential to have less of an influence on the color of the final restoration.…”

Section: Introductionmentioning

confidence: 99%

The Effect of Light Curing Source on the Residual Yellowing of Resin Composites

Brackett¹,

Brackett²,

Browning³

2007

Operative Dentistry

View full text Add to dashboard Cite

Laboratory Research SUMMARYPurpose. This study evaluated the amount of residual yellow in cured resin composites when polymerizing with either a quartz-tungsten-halogen (QTH) or blue light-emitting diode (LED). Material and Methods: Twelve shades (bleaching to conventional shades) of microfill, hybrid and microhybrid resin composite specimens (n=10) were polymerized with both light types. All the materials contained only camphorquinone as the photoinitiator. After exposure, the specimens were stored in the dark for 24 hours. Then, the specimen color parameters were recorded (L*, a*, b* and C* ab ) and color differences (ΔE* ab ) were determined by examining for changes among the test combinations. Group comparisons were examined using ANOVA and the Tukey-Kramer post-hoc test, and pairwise comparisons were made using Student's t-tests at a pre-set alpha of 0.05. Results: When a significant difference in residual yellow was noted, the QTH light produced a greater yellow tinge than most comparisons using the LED. The potential for producing more residual yellowing could not be anticipated with respect to composite filler classification or shade, as this effect may be more dependent on individual product composition. The extent to which residual yellowing differences were noted between light curing unit types fell within levels considered detectable by the human eye (ΔE>2.0). Clinical RelevanceThe selection of light curing unit (quartz-tungsten-halogen or blue light-emitting diode), composite classification and shade have an influence on the amount of residual yellow after photocuring and, in some combinations, the color difference may be visually detectable.

show abstract

Section: Introductionmentioning

confidence: 99%

The Effect of Light Curing Source on the Residual Yellowing of Resin Composites

Brackett¹,

Brackett²,

Browning³

2007

Operative Dentistry

View full text Add to dashboard Cite

show abstract

“…This behavior is not in agreement with Beer-Lambert's law and Figure 3, but has already been attributed elsewhere to photobleaching. [12,13,33,34] The irradiation time has thus been set to 3 min, so that Laromer 1 double bonds can react to about 80% at the surface and to less than a few percent in depth ( Figure 4).…”

Section: Resultsmentioning

confidence: 99%

Gradient Structure Polymer Obtained from a Homogeneous Mixture: Synthesis and Mechanical Properties

Noblet¹,

Désilles²,

Lecamp³

et al. 2006

Macro Chemistry & Physics

View full text Add to dashboard Cite

Summary: The synthesis of a polymer that exhibits a gradient in mechanical properties, by means of a new method recently developed in our laboratory, is described. The synthesis involves two commercial resins, Laromer® LR 8986 and Laromer® LR 9000. In a first step, an acrylic double bond photopolymerization gradient is created under UV exposure thanks to the decay of UV light intensity through the sample thickness. In a second step, a thermal crosslinking reaction is realized to form a polyurethane network in order to set the obtained gradient. The experimental conditions required to obtain and keep the gradient are investigated by FT‐IR and UV spectroscopies. Thus, an 80% acrylic double bond conversion gradient is obtained in the ultimate 5 mm thick material. Dynamic mechanical analysis reveals an important difference between both sides of the material, the irradiated surface being hard at ambient temperature, meanwhile the underside remains soft.Acrylic double bond conversion after 3 min of irradiation at 30 °C on materials of various thicknesses.magnified imageAcrylic double bond conversion after 3 min of irradiation at 30 °C on materials of various thicknesses.

show abstract

“…Bisacyl phosphine oxides were introduced as a new class of α-cleavage photoinitiators over the year, which has an absorption bands in the near UV/visible region. 11,12 Cloisite 15A (CEC=125 meq/100 g, Southern Clay Products, Gonzales, TX), organically treated with quaternary ammonium salt montmorillonite (MMT) was added as a nanoclay without further surface treatment.…”

Section: Methodsmentioning

confidence: 99%

Effect of Crosslinking Agent on Adhesion Properties of UV Curable 2-EHA/AA Pressure Sensitive Adhesive

Kim¹,

Min²

2015

Polymer Korea

View full text Add to dashboard Cite

UV-cured acrylic copolymer pressure sensitive adhesive (PSA) having different amounts of crosslinking agents were prepared and adhesion properties were investigated. 0.01 wt% of MMT clay was dispersed in 2-ethylhexyl acrylate (2-EHA)/acrylic acid (AA) monomer mixture containing 0, 0.05, 0.1 and 0.3 wt% 1,6-hexandiol diacrylate (HDDA) for crosslinking. It was investigated that the curing behavior and surface chemistry of PSAs were merely affected by the presence of MMT clays. On the other hand, adhesive properties were influenced by the MMT addition; a cohesive failure was restrained due to improved molecular elasticity even in uncrosslinked acrylic PSAs. However, it was also appeared that combination of 0.3 wt% crosslinking agent and MMT loading might result in the damage of adhesion properties of PSAs possibly due to the lack of chain flexibility. In our studies, it is suggested that the 2-EHA/AA PSAs incorporating 0.01 wt% of MMT and crosslinked with 0.05 wt% of HDDA exhibited the balanced adhesion properties without severe cohesive failure during strip.

show abstract

Recent developments in photoinitiators

Cited by 116 publications

References 18 publications

The Effect of Light Curing Source on the Residual Yellowing of Resin Composites

The Effect of Light Curing Source on the Residual Yellowing of Resin Composites

Gradient Structure Polymer Obtained from a Homogeneous Mixture: Synthesis and Mechanical Properties

Effect of Crosslinking Agent on Adhesion Properties of UV Curable 2-EHA/AA Pressure Sensitive Adhesive

Contact Info

Product

Resources

About