Suspension Polymerization Processes

Abstract

Several processes can be employed for manufacturing of polymer materials. Each process presents some intrinsic features that lead to production of resins with peculiar structural and morphological characteristics that define the final polymer properties and the end‐use application of the obtained polymer material. Suspension polymerization processes are extensively used because of their many advantages, including easy separation of the polymer particles, easy removal of the heat of reaction, easy temperature control, and low levels of impurities and additives in the final polymer resin. For this reason, suspension polymerization processes are suitable for production of polymer resins intended for many distinct applications, including biotechnological, medical, and dental applications. The main objective of this article is to discuss the fundamental aspects of suspension polymerization processes, focusing upon the effects of the main process variables on the performance of suspension polymerizations. Representative types of suspension polymerization (eg, pearl, precipitation, suspension‐emulsion, reverse, microsuspension, and seeded polymerizations), copolymerization, determination of reactivity ratios, and typical operation conditions practiced in commercial processes are also discussed.

In Situ Incorporation of Praziquantel in Polymer Microparticles through Suspension Polymerization for Treatment of Schistosomiasis

“…Polymerization takes place inside the monomer droplets, which are progressively converted into viscous and sticky granules, and finally become rigid polymer particles with characteristic sizes ranging from 50 to 500 µm. [27][28][29] If the process is well controlled, the final obtained polymer powder presents the form of spherical beads that are easy to manipulate and separate through filtration. [30] Despite the previously described advantageous characteristics, most homopolymer beads are insensitive to physiological changes of the human body, including the pH variations experienced along the gastrointestinal tract.…”

Photopolymerization in dispersed systems

“…The most common ionic types are sodium dodecyl sulfate (SDS) and cetyl trimethyl ammonium bromide (CTAB), widely found in conventional emulsion polymerization. With regard to non-ionic surfactants, poly(ethylene oxide) (PEO) and poly(vinyl pyrrolidone) (PVP) have been used in dispersion photopolymerization [78] and poly(vinyl alcohol) (PVA) in suspension polymerization [79]. There are also examples of polymeric surfactants including photocleavable groups [80].…”

Evaluation of conversion during the synthesis of aluminum (III) methacrylate-based copolymers using Raman spectroscopy and multivariate curve resolution

“…Poly(vinyl acetate) synthesized in heterogeneous polymerization process usually requires 4 to 6 h of reaction to polymerize completely (depending on the concentration of the free radical initiator of polymerization and reaction temperature) [56,57]. On the other hand, MCMs need long reaction times.…”

“…This behavior arises from the fact that a large amount of free radical initiator was employed. The major quantity of BPO is necessary to promote the copolymerization between organic and inorganic monomers, but, as a result, the excess of radical specie favors the formation small polymer chains, lowering the average molar masses of the copolymeric materials and consequently decreasing the thermal stability [12,[56][57][58]. In those cases, the degradation of polymeric chains initiates at the extremity of the chain which were located the aromatic ester from the benzoyl peroxide radical.…”