Kinetics and mechanism of vinyl chloride polymerization

Abstract

INTRODUCTION 1. CHAIN TRANSFER REACTION IN VINYL CHLORIDE POLYMERIZATION 2. BULK AND SUSPENSION POLYMERIZATION 2.1. Particle formation 2.2. Kinetics of polymerizatibn 3. ORDINARY EMULSION POLYMERIZATION 3.1. Particle formation 3.1.1. Below CMC 3.1.2. Above CMC 3.2. Kinetics and mechanism 3.3. Seed polymerization 4. EMULSION POLYMERIZATION WITH INITIATION IN MONOMER DROPLETS • THERMODYNAMIC TREATMENT OF FORMATION AND STABILITY 4.1. Polymerization of monomer emulsions formed by the diffusion process 4.2. Polymerization of monomer emulsions formed by spontaneous emulsification with mixed emulsifier systems 5. POLYMERIZATION AT SUB-SATURATION PRESSURES LIST OF SYMBOLS REFERENCES Abstract Kinetic models for formation of CH2C1 branch units based on headto head addition and the first order interruption of the growing chain with formation of Cl. and H. radicals are discussed. Some features of the formation and stabilization of primary particles in bulk and suspension polymerization are reviewed. Different kinetic models for bulk and suspension polymerization are critically reviewed. Particle formation in emulsion polymerization below and above CMC is treated, due consideration being given to the desorption and reabsorption of radicals. The kinetics of emulsion polymerization is discussed in detail. Desorption and reabsorption of radicals are discussed as well as the possibility of termination in the aqueous phase. Steady and non steady state treatments in seed polymerization are discussed. Thermodynamic principles for the formation and stability of monomer emulsions are treated. Initiation in monomer droplets with direct formation of latex particles in the 0.2-1.5 pm range as well as monodisperse particles in the 2-5 pm range are described. Spontaneous emulsification with formation of relatively stable monomer emulsions with different mixed emulsifier systems and subsequent polymerization with initiation in the monomer droplets is discussed. Polymerization under conditions corresponding to sub-saturation pressures can be achieved by addition of a low molecular weight, water insoluble compound to the monomer phase.Kinetic models for formation of CH2C1 branch units based on headto head addition and the first order interruption of the growing chain with formation of Cl. and H. radicals are discussed. Some features of the formation and stabilization of primary particles in bulk and suspension polymerization are reviewed. Different kinetic models for bulk and suspension polymerization are critically reviewed. Particle formation in emulsion polymerization below and above CMC is treated, due consideration being given to the desorption and reabsorption of radicals. The kinetics of emulsion polymerization is discussed in detail. Desorption and reabsorption of radicals are discussed as well as the possibility of termination in the aqueous phase. Steady and non steady state treatments in seed polymerization are discussed. Thermodynamic principles for the formation and stability of monomer emulsions are treated. Initiation in monomer droplets with direct formation of latex particles in the 0.2-1.5 pm range as well as monodisperse particles in the 2-5 pm range are described. Spontaneous emulsification with formation of relatively stable monomer emulsions with different mixed emulsifier systems and subsequent polymerization with initiation in the monomer droplets is discussed. Polymerization under conditions corresponding to sub-saturation pressures can be achieved by addition of a low molecular weight, water insoluble compound to the monomer phase.