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RadTech
UV/EB Technology Conference & Expo 2008
May 4-7, 2008
Lakeside Center at McCormick Place
Chicago, Illinois - United States of America
KINETICS
A New Method of Analyzing
Double Bond Conversion As A Function
of Film Thickness
Rong Bao, Fusion UV Systems, Inc.
Abstract:
New method of analyzing a depth profile of double bond conversion
as a function of film thickness will be presented. By using a combination
of statistical calculation and FTIR, a new approach to analyze the
depth profile of conversion "layer by layer" in the characterization
of photo polymerization will be discussed. Utilizing a formula (X1
+ X2 + …… Xn) / n = Average conv. n = 1,2,3…. n: a
number of layer (5 microns), an average conversion of any 5 micron
section can be calculated from prior 5 micron conversion and total
average conversion. More detail information of photo-polymerization,
such as the depth profile of conversion and a difference in conversion
between the top 5 microns and the bottom 5 microns in a 25 micron
film as a function of film thickness can be obtained. This investigation
will be accomplished using a variation of film thickness, photo bleaching
PhI (Irg. 819) and un-photo bleaching PhI (Irg. 184) as well as the
concentration of PhIs in the presence of air and in absence of air.
Some commercial formulations will also be analyzed using this new
approach. An influence of mixture of PhIs on the double bond conversion
at given depth of a cured film in a 25-micron film will be discussed.
Results of analyzing double bond conversion between traditional FTIR
and the new approach (statistical calculation / FTIR) will be compared.
Effect
of Water on Photopolymerization of Tributylmethylammonium-based
(Meth)acrylate Ionic Liquids
Hui Zhou, University of Southern Mississippi
Abstract: Photocurable tributylmethylammonium-based (meth)acrylate
ionic liquid monomers have been synthesized from the neutralization
reaction between tributylmethylammonium hydroxide and acid-containing
(meth)acrylates. The photopolymerization kinetics of these ionic
liquids and the effect of water on the polymerization rate have
been investigated and discussed. The addition of water into ionic
liquid monomers dramatically affects the curing rates.
Microstructural
Aspects of Radiation Cured Multiacrylates
Xavier COQUERET, Universite de Reims
Champagne Ardenne
Abstract: The kinetic and microstructural aspects of the
radiation-induced polymerisation of multiacrylates have been investigated
with emphasis on the reaction rate and subsequent curing that are
strongly affected by network formation. On the basis of the features
determined by solid state NMR relaxation experiments and on measurements
of volume contraction as a function of monomer conversion, a common
scenario can be proposed to describe the course of polymerisation
involving multifunctional acrylate monomers submitted to UV and
EB initiation.
The
Effect of Atmospheric Factors on Kinetics of Acryate/Epoxide Hybrid
Photopolymerizations
Ho Seop Eom, CBE, University of Iowa
Abstract: Hybrid photopolymerizations of urethane acrylates/cycloaliphatic
epoxides were conducted to evaluate the effect of atmospheric variables,
such as oxygen and water, on kinetics. Simultaneously and sequentially
polymerized samples achieved by patterned illumination will be compared
to see how kinetics and conversion in two different reaction sequences
are affected by those atmospheric variables. Raman spectroscopy
will be used to obtain the polymerization rate and conversion in
real time. Raman microscopic technique will be used for z-directional
depth profiling to validate the oxygen-diffusion-affected region
on the surface of each hybrid system.
The
Use of Thin Film Calorimetry in Profiling Norrish Type I and
Norrish Type II Photoinitiators
Celeste A. Diener, UV Process Supply,
Inc.
Abstract: The use of Thin Film Calorimetry (TFC) and monochromatic
Ultraviolet Light Emitting Diodes (UV-LEDs) to profile Norrish Type
I cleavage photoinitiators and Norrish Type II cleavage photoinitiators
in the curing of generic epoxides, polyesters, and urethanes. The
methods of how the data is collected and compiled and the profiles
of cure performance using five different wavelengths are reported
on.
TR
ESR Study of Elementary Reactions of Photoinitiation and Termination
Igor V. Khudyakov, Bomar Specialties
Abstract: Results of time-resolved (TR) ESR study of direct
and sensitized photoinitiation of polymerization of acrylates are
presented. TR ESR allows unequivocal identification of transient
radicals formed during photoinitiation. TR ESR study of termination
of free radicals of photoinitiators with stable nitroxyls and binitroxyls
are discussed. The results have been never presented at any conference.
The most recent data is published in 2007: E. Sartori, I.V. Khudyakov,
X. Lei, N.J. Turro, JACS 2007, 129, 7785
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