Emulsifier-free emulsion polymerization of tetrafluoroethylene by radiation. II. Effects of reaction conditions on polymer particle size and number

1979 ◽  
Vol 17 (1) ◽  
pp. 111-127 ◽  
Author(s):  
Takeshi Suwa ◽  
Terutaka Watanabe ◽  
Tadao Seguchi ◽  
Jiro Okamoto ◽  
Sueo Machi
2013 ◽  
Vol 395-396 ◽  
pp. 403-406 ◽  
Author(s):  
Li Bao Mei ◽  
Xiao Qin Xiao ◽  
Yong Li ◽  
Yan Lin Sun

The variation trend of polymer particle size under different emulsifier concentrations in emulsion polymerization of styrene were investigated in this paper. The results show that the particle number increases and particle size decreases with the increase of emulsifier concentration. But the particle size growth is controlled by the rate of the monomer migration from water medium to the growing micelles.


Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1958
Author(s):  
Jae-Jung Park ◽  
Yongsoo Kim ◽  
Chanmin Lee ◽  
Donghyun Kim ◽  
Wonjun Choi ◽  
...  

Emulsion polymerization presents the disadvantage that the physical properties of polymer particles are altered by surfactant adsorption. Therefore, in the soap-free emulsion polymerization method, a hydrophilic initiator is utilized while inducing repulsion among particles on the polymer particle surface, resulting in stable polymer particle production. In this study, we developed a methodology wherein spherical and uniform poly(styrene-co-maleic anhydride) (PSMA)/polyethyleneimine (PEI) core–shell nanoparticles were prepared. Further, their morphology was analyzed. During PSMA polymerization, the addition of up to 30% maleic anhydride (MA) resulted in stable polymerization. In PSMA/PEI nanoparticle fabrication, the number of reactants increased with increased initial monomer feed amounts; consequently, the particle size increased, and as the complete monomer consumption time increased, the particle distribution widened. The styrene (St) copolymer acted as a stabilizer, reducing particle size and narrowing particle distribution. Furthermore, the monomers were more rapidly consumed at high initiator concentrations, irrespective of the initiator used, resulting in increased particle stability and narrowed particle distribution. The shell thickness and particle size were PEI feed ratio dependent, with 0.08 being the optimal PEI-to-MA ratio. The fabricated nanoparticles possess immense potential for application in environmental science and in chemical and health care industries.


1970 ◽  
Vol 43 (1) ◽  
pp. 74-94 ◽  
Author(s):  
J. L. Gardon

Abstract Emulsion polymerization is one of the most important processes for the manufacture of polymers for rubbers, plastics, coatings, finishes, and adhesives. By the correct choice of comonomers, initiators, surfactants, and reaction conditions, a great variety of latex products are manufactured which meet many specific requirements in their applications. However, there is a great gap between this mostly empirically developed and sophisticated technology and our scientific understanding of it. The present paper presents a theory based on a single internally consistent model which predicts several experimentally available data of emulsion polymerization: the particle size, the conversion—time relationship, the dependence of particle size and molecular weight on conversion, and the influence of surfactant, of initiator and of monomer. This theory is based on extension of the assumptions first proposed by Smith and Ewart and Haward, and later modified by Stockmayer and O'Toole. It differs from these earlier theories in that the derived relationships are quantitative and contain no adjustable parameters. Also, the validity limits of the predictions are defined. The present form of the theory does not apply to all monomers, initiators, surfactants and reaction conditions commonly used in the practice of emulsion polymerization although its predictions are in good accord with experimental results obtained with model systems complying with the assumed conditions.


Sign in / Sign up

Export Citation Format

Share Document