Photoinitiators for Polymer Synthesis
Scope, Reactivity, and Efficiency

Photoinitiating systems for polymerization reactions are largely encountered in a variety of traditional and high-tech sectors, such as radiation curing, (laser) imaging, (micro)electronics, optics, and medicine.

This book extensively covers radical and nonradical photoinitiating systems and is divided into four parts:

* Basic principles in photopolymerization reactions
* Radical photoinitiating systems
* Nonradical photoinitiating systems
* Reactivity of the photoinitiating system

The four parts present the basic concepts of photopolymerization reactions, review all of the available photoinitiating systems and deliver a
thorough description of the encountered mechanisms. A large amount of experimental and theoretical data has been collected herein. This
book allows the reader to gain a clear understanding by providing a general discussion of the photochemistry and chemistry involved.
The most recent and exciting developments, as well as the promising prospects for new applications, are outlined.

INTRODUCTION

PART I: Basic Principles and Applications of Photopolymerization Reactions

PHOTOPOLYMERIZATION AND PHOTO-CROSS-LINKING LIGHT SOURCES
Electromagnetic Radiation
Characteristics of a Light Source
Conventional and Unconventional Light Sources

EXPERIMENTAL DEVICES AND EXAMPLES OF APPLICATIONS
UV Curing Area: Coatings, Inks, Varnishes, Paints, and Adhesives
Conventional Printing Plates
Manufacture of Objects and Composites
Stereolithography
Applications in Microelectronics
Laser Direct Imaging
Computer-to-Plate Technology
Holography
Optics
Medical Applications
Fabrication of Nano-Objects through a Two-Photon Absorption Polymerization
Photopolymerization Using Near-Field Optical Techniques
Search for New Properties and New End Uses
Photopolymerization and Nanotechnology
Search for a Green Chemistry

PHOTOPOLYMERIZATION REACTIONS
Encountered Reactions, Media, and Experimental Conditions
Typical Characteristics of Selected Photopolymerization Reactions
Two-Photon Absorption-Induced Polymerization
Remote Curing: Photopolymerization without Light
Photoactivated Hydrosilylation Reactions

PHOTOSENSITIVE SYSTEMS
General Properties
Absorption of Light by a Molecule
Jablonski's Diagram
Kinetics of the Excited State Processes
Photoinitiator and Photosensitizer
Absorption of a Photosensitive System
Initiation Step of a Photoinduced Polymerization
Reactivity of a Photosensitive System

APPROACH OF THE PHOTOCHEMICAL AND CHEMICAL REACTIVITY
Analysis of the Excited-State Processes
Quantum Mechanical Calculations
Cleavage Process
Hydrogen Transfer Processes
Energy Transfer
Reactivity of Radicals

EFFICIENCY OF A PHOTOPOLYMERIZATION REACTION
Kinetic Laws
Monitoring the Photopolymerization Reaction
Efficiency versus Reactivity
Absorption of Light by a Pigment
Oxygen Inhibition
Absorption of Light Stabilizers
Role of the Environment

PART II: Radical Photoinitiating Systems

ONE-COMPONENT PHOTOINITIATING SYSTEMS
Benzoyl-Chromophore-Based Photoinitiators
Substituted Benzoyl-Chromophore-Based Photoinitiators
Hydroxy Alkyl Heterocyclic Ketones
Hydroxy Alkyl Conjugated Ketones
Benzophenone- and Thioxanthone-Moiety-Based Cleavable Systems
Benzoyl Phosphine Oxide Derivatives
Phosphine Oxide Derivatives
Trichloromethyl Triazines
Biradical-Generating Ketones
Peroxides
Diketones
Azides and Aromatic Bis-Azides
Azo Derivatives
Disulfide Derivatives
Disilane Derivatives
Diselenide and Diphenylditelluride Derivatives
Digermane and Distannane Derivatives
Carbon -
Germanium Cleavable-Bond-Based Derivatives
Carbon -
Silicon and Germanium 'Silicon Cleavable' Bond-Based Derivatives
Silicon Chemistry and Conventional Cleavable Photoinitiators
Sulfur -
Carbon Cleavable-Bond-Based Derivatives
Sulfur -
Silicon Cleavable-Bond-Based Derivatives
Peresters
Barton's Ester Derivatives
Hydroxamic and Thiohydroxamic Acids and Esters
Organoborates
Organometallic Compounds
Metal Salts and Metallic Salt Complexes
Metal-Releasing Compound
Cleavable Photoinitiators in Living Polymerization
Oxyamines
Cleavable Photoinitiators for Two-Photon Absorption
Nanoparticle-Formation-Mediated Cleavable Photoinitiators
Miscellaneous Systems
Tentatively Explored UV-Light-Cleavable Bonds

TWO-COMPONENT PHOTOINITIATING SYSTEMS
Ketone-/Hydrogen-Donor-Based Systems
Dye-Based Systems
Other Type II Photoinitiating Systems

MULTICOMPONENT PHOTOINITIATING SYSTEMS
Generally Encountered Mechanism
Other Mechanisms
Type II Photoinitiator/Silane: Search for New Properties
Miscellaneous Multicomponent Systems

OTHER PHOTOINITIATING SYSTEMS
Photoinitiator-Free Systems or Self-Initiating Monomers
Semiconductor Nanoparticles
Self-Assembled Photoinitiator Monolayers

PART III: Nonradical Photoinitiating Systems

CATIONIC PHOTOINITIATING SYSTEMS
Diazonium Salts
Onium Salts
Organometallic Derivatives
Onium Salt/Photosensitizer Systems
Free-Radical-Promoted Cationic Photopolymerization
Miscellaneous Systems
Photosensitive Systems for Living Cationic Polymerization
Photosensitive Systems for Hybrid Cure

ANIONIC PHOTOINITIATORS
Inorganic Complexes
Organometallic Complexes
Cyano Derivative/Amine System
Photosensitive Systems for Living Anionic Polymerization

PHOTOACID GENERATORS (PAG) SYSTEMS
Iminosulfonates and Oximesulfonates
Naphthalimides
Photoacids and Chemical Amplification

PHOTOBASE GENERATORS (PBG) SYSTEMS
Oxime Esters
Carbamates
Ammonium Tetraorganyl Borate Salts
N-Benzylated-Structure-Based Photobases
Other Miscellaneous Systems
Photobases and Base Proliferation Processes

PART IV: Reactivity of the Photoinitiating System

ROLE OF THE EXPERIMENTAL CONDITIONS IN THE PERFORMANCE OF A RADICAL PHOTOINITIATOR
Role of Viscosity
Role of the Surrounding Atmosphere
Role of the Light Intensity

REACTIVITY AND EFFICIENCY OF RADICAL PHOTOINITIATORS
Relative Efficiency of Photoinitiators
Role of the Excited-State Reactivity
Role of the Medium on the Photoinitiator Reactivity
Structure/Property Relationships in Photoinitiating Systems

REACTIVITY OF RADICALS TOWARD OXYGEN, HYDROGEN DONORS, MONOMERS, AND ADDITIVES: UNDERSTANDING AND DISCUSSION
Alkyl and Related Carbon-Centered Radicals
Aryl Radicals
Benzoyl Radicals
Acrylate and Methacrylate Radicals
Aminoalkyl Radicals
Phosphorus-Centered Radicals
Thiyl Radicals
Sulfonyl and Sulfonyloxy Radicals
Silyl Radicals
Oxyl Radicals
Peroxyl Radicals
Aminyl Radicals
Germyl and Stannyl Radicals
Boryl Radicals
Lophyl Radicals
Iminyl Radicals
Metal-Centered Radicals
Propagating Radicals
Radicals in Controlled Photopolymerization Reactions
Radicals in Hydrosilylation Reactions

REACTIVITY OF RADICALS: TOWARDS THE OXIDATION PROCESS
Reactivity of Radicals toward Metal Salts
Radical/Onium Salt Reactivity in Free-Radical-Promoted Cationic Photopolymerization

INDEX

Jean-Pierre Fouassier was a Professor of Physical Chemistry at the University of Haute Alsace, Mulhouse until October 2011. He was Head of a University/CNRS Laboratory, a Member of the Organizing Committees of many International Conferences, a Director of the Ecole Nationale
Superieure de Chimie de Mulhouse and a Member of the French National University Council. His research interests focused both on the excited-state processes in photoinitiatiors and photosensitizers and their application to photopolymerization reactions in various areas. He has
published a total of around 600 research articles, book chapters, review papers, technical papers, proceedings, and patents, as well as authoring one book, one technical report and editing 6 books (14 volumes).

Jacques Lalevee is a Professor of Physical Chemistry at the University of Haute Alsace, Mulhouse. His research interests are focused on free-radical chemistry and the design of efficient systems for photopolymerization processes. He has published a total of around 160 research
articles, technical papers, proceedings, patents, review papers, and book chapters. He is also a Member of the Institut Universitaire de France (Paris).