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Molecularly Imprinted and Ion Imprinted Polymers for Selective Recognition and Sensing of Organics and Ions
Published in Asit Baran Samui, Smart Polymers, 2022
Pankaj E. Hande, Asit Baran Samui
Several preparation methods have been reported for the development of MIPs/IIPs, such as bulk polymerization, suspension polymerization, emulsion polymerization, dispersion polymerization, and precipitation polymerization. In bulk polymerization, the initiator, a template-monomer, and a cross-linker are added together in one phase where the initiator is completely soluble in the template-monomer and cross-linker. Suspension polymerization is a heterogeneous radical polymerization where the template, monomer, cross-linker, and initiator are soluble in each other and mixed together by high-speed mechanical stirring in a liquid phase such as water to get polymeric beads. In emulsion polymerization, the template, monomer, and cross-linker are polymerized using an oil-in-water emulsion in the presence of a surfactant where the initiator is water-soluble. Precipitation polymerization is the type of radical polymerization where the template, monomer, cross-linker, and initiator are dissolved in a solvent but during the process of reaction (polymerization), precipitation takes place.
Characteristics of Polymers and Polymerization Processes
Published in Manas Chanda, Plastics Technology Handbook, 2017
Suspension polymerization combines the advantages of both the bulk and solution polymerization techniques. It is used extensively in the mass production of vinyl and related polymers. In suspension polymerization (also referred to as bead or pearl polymerization), the monomer is suspended as droplets by efficient agitation in a large volume (continuous phase) of nonsolvent, commonly referred to as the dispersion or suspension medium. Water is used as the suspension medium for water insoluble monomers because of its obvious advantages. Styrene, methyl methacrylate, vinyl chloride, and vinyl acetate are polymerized by this suspension process.
Monomers, Polymers, and Plastics
Published in James G. Speight, Handbook of Petrochemical Processes, 2019
In suspension polymerization, the monomer is first dispersed in a liquid, such as water and mechanical agitation keeps the monomer dispersed. Initiators should be soluble in the monomer and stabilizers, such as talc or polyvinyl alcohol, preventing polymer chains from adhering to each other and keep the monomer dispersed in the liquid medium. As a result, the final polymer appears in a granular form. Suspension polymerization produces polymers more pure than those from solution polymerization due to the absence of chain transfer reactions. As in a solution polymerization, the dispersing liquid helps control the heat of the reaction.
Synthesis and radiation grafting modification of hydroxyl controlled AM/HEMA polymer microspheres
Published in Journal of Dispersion Science and Technology, 2021
Zhiyong Wang, Meiqin Lin, Zhaoxia Dong, Juan Zhang, Zihao Yang
Much attention of polymer particles have been played to the research field of material in recent years,[1–4] because of its many features, for instance, monodisperse, highly cross-linked, smooth-faced, micrometer-sized spherical. Suspension polymerization has proven to be an efficient approach for such purpose because of its easy operation and dispense with any deactivator and catalyst compared with other polymerizations.[5–7] Since its first discovery in 1995,[8–10] atomic transfer radical polymerization (ATRP) has attracted considerable attention for its versatility in the controlled design of macromolecular structures. According to their different initiating species used, two kinds of ATRP methods are available, which are normal ATRP and reverse ATRP.[11] Xie et al. put forward a mathematical model that is developed to characterize the batch atom transfer radical suspension polymerization (batch suspension ATRP[12–14]), for the first time, the morphological and molecular properties of particles, as well as their dynamics in methyl methacrylate ATRP can be simultaneously simulated by solving the model that consists of ATRP kinetic equations, moment equations, a phase equilibrium equation for calculating equilibrium monomer distributions in various phases, and a particle population balance model.[15] In addition, toxic solvents will not be used in the inverse atom transfer radical suspension polymerization (RATRSP) process (e.g., pyridine, tetrahydrofuran, etc.).[16–20]