Kinetic Model of Pulsed Laser-Initiated Polymerization in the Presence of Chain Transfer to Monomer

Yan, Deyue; Zhang, Minfu; Schweer, Johannes

doi:10.1021/ma9513168

Cited by 5 publications

(16 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Then the polymer chain grows by repeating this same step, which is referred to as chain propagation, where M n • represents a macro-radical made up of n monomeric units ( n ≥ 1); and k p (cm 3 /mol s) is the rate constant of propagation. In this model, no distinction is made between the different steps made as each monomeric unit is attached. − ,− Simultaneously, the macro-radicals are also undergoing the following reactions:…”

Section: Photochemical Kineticsmentioning

confidence: 99%

High Intensity Response of Photopolymer Materials for Holographic Grating Formation

et al. 2010

View full text Add to dashboard Cite

In order to further develop the understanding of photopolymer materials, a more complete physical model has become necessary. In particular, a more accurate description of the photochemical mechanisms occurring during the photopolymerization processes is needed. Generally, in photopolymers, the photosensitizer absorbs light of an appropriate wavelength, becoming excited and causing the production of primary radicals, R • . In free radical polymerization systems, the generation of R • is a key factor in determining how much monomer is polymerized. This in turn is closely related to the refractive index modulation formed during holographic recording. In this article, we incorporate a detailed photoinitiation model into the nonlocal photopolymerization driven diffusion (NPDD) model. This model describes the following: (1) Photon absorption behavior and primary radical generation during initiation;(2) nonlocal macro-radical chain growth through propagation; (3) oxygen diffusion and replenishment for inhibition; (4) multiple termination mechanisms. This extended model is experimentally validated for high intensity holographic exposures to a polyvinylalcohol/acrylamide based photopolymer material.

show abstract

Section: Photochemical Kineticsmentioning

confidence: 99%

High Intensity Response of Photopolymer Materials for Holographic Grating Formation

et al. 2010

View full text Add to dashboard Cite

show abstract

“…. The same approach has been used by Yan et al [24] to derive analytical expressions for the calculation of MWDs for Scheme 2. To derive closed solutions of the rate equations for Scheme 1 and 2, Olaj et al [1,[25][26][27] have ignored the Poisson broadening in chain propagation.…”

Section: Theorymentioning

confidence: 99%

Simulation of Molecular Weight Distributions Obtained by Pulsed Laser Polymerization (PLP): New Analytical Expressions Including Intramolecular Chain Transfer to the Polymer

Nikitin

Castignolles

Charleux

et al. 2003

Macro Theory & Simulations

View full text Add to dashboard Cite

A new approach for the simulation of PLP (pulsed laser polymerization) is presented. This approach allows one to obtain new analytical solutions for different polymerization schemes, including either chain transfer to the monomer or intramolecular chain transfer to the polymer. The first results of the simulation of PLP experiments on n‐butyl acrylate at 20 °C and ambient pressure are presented.MWDs simulated for PLP of n‐butyl acrylate, in bulk at 20 °C and ambient pressure using three models: the model with intramolecular chain transfer to the polymer (solid line), the model with chain transfer to monomer (dashed line), and the classical model (dotted line).imageMWDs simulated for PLP of n‐butyl acrylate, in bulk at 20 °C and ambient pressure using three models: the model with intramolecular chain transfer to the polymer (solid line), the model with chain transfer to monomer (dashed line), and the classical model (dotted line).

show abstract

“…Integrating the d function in Equation (19) and using Equation (15) to express f env in terms of C yields…”

Section: Dead Mwdmentioning

confidence: 99%

“…Such numerical approaches have so far been employed both in the absence [11,17,18] and the presence of chain transfer. [13,19,16] The effects of experimental broadening have been addressed numerically in refs. [17,16] Analytical solutions of PLP dynamics are also very desirable.…”

Section: Introductionmentioning

confidence: 99%

Pulsed Laser Polymerization at Low Conversions: Broadening and Chain Transfer Effects

O’Shaughnessy

Vavylonis

2003

Macro Theory & Simulations

View full text Add to dashboard Cite

Pulsed laser polymerization (PLP) is widely employed to measure propagation rate coefficients k p in free radical polymerization. Various properties of PLP have been established in previous works, mainly using numerical methods. The objective of this paper is to obtain analytical results. We obtain the most general analytical solution for the dead chain molecular weight distribution (MWD) under low conversion conditions which has been hitherto obtained. Simultaneous disproportionation and combination termination processes are treated. The hallmarks of PLP are the dead MWD discontinuities located at integer multiples of n 0 = k p t 0 C M , where t 0 is the laser period and C M is the monomer concentration. We show that chain transfer reduces their amplitude by factors e −ctrLn0 , consistent with numerical results obtained by other workers. Here c tr is the chain transfer coefficient and Ln 0 (L =integer) are the discontinuity locations. Additionally, transfer generates a small amplitude continuous contribution to the MWD. These results generalize earlier analytical results which were obtained for the case of disproportionation only. We also considered 2 classes of broadening: (i) Poisson broadening of growing living chains and (ii) intrinsic broadening by the MWD measuring equipment (typically gel permeation chromatography, GPC). Broadening smoothes the MWD discontinuities. Under typical PLP experimental conditions, the associated inflection points are very close to the discontinuities of the unbroadened MWD. Previous numerical works have indicated that the optimal procedure is to use the inflection point to infer k p . We prove that this is a correct procedure provided the GPC resolution σ is better than n 1/2 0 . Otherwise this underestimates Ln 0 by an amount of order σ 2 /n 0 .

show abstract

Kinetic Model of Pulsed Laser-Initiated Polymerization in the Presence of Chain Transfer to Monomer

Cited by 5 publications

References 12 publications

High Intensity Response of Photopolymer Materials for Holographic Grating Formation

High Intensity Response of Photopolymer Materials for Holographic Grating Formation

Simulation of Molecular Weight Distributions Obtained by Pulsed Laser Polymerization (PLP): New Analytical Expressions Including Intramolecular Chain Transfer to the Polymer

Pulsed Laser Polymerization at Low Conversions: Broadening and Chain Transfer Effects

Contact Info

Product

Resources

About