The effect of the pristine sodium montmorillonite (Na-MMT) on the styrene emulsion polymerizations with different concentrations of SDS ([SDS]) was investigated. At constant [SDS], the polymerization rate is faster for the run with 1 wt.% Na-MMT compared to the counterpart without Na-MMT. Micelle nucleation predominates in the polymerizations with [SDS] = 13 mM. On the other hand, the contribut...

INTRODUCTION Since many decades, polyethylene (PE) is one of the commodity polymers which has become ubiquitous because of its low price and good mechanical properties. Hence, the number of applications of the material is huge and many millions of tons are produced worldwide annually. However, PE has hardly played any role in the emerging field of nanotechnology so far. This is due to the probl...

Catalytic aqueous polymerization of butadiene by the cobalt catalyst system [Co(C8H13)(C4H6)]/CS2 affords colloidally stable latices of highly crystalline syndiotactic 1,2-polybutadiene (Tm ) 190 °C, ∆Hc ) 60 J/g, Mw ∼ 105 g/mol, 97% 1,2, 3% 1,4-cis). Catalyst modification with reagents containing electrophilic carbon atoms (e.g., aromatic formamides) strongly decreases polymer crystallinity (T...

The application of atypical experimental methods such as conductivity measurements, optical microscopy, and nonstirred polymerizations to investigations of the 'classical' batch ab initio emulsion polymerization of styrene revealed astonishing facts. The most important result is the discovery of spontaneous emulsification leading to monomer droplets even in the quiescent styrene in water system...

Run-to-run optimization exploits the repetitive nature of batch processes to adapt the operating policy in the presence of uncertainty. For problems where terminal constraints play a dominant role in the optimization, the system can be operated close to the optimum simply by satisfying terminal constraints. The input is parameterized by using the knowledge of the shape of the optimal solution a...

The determination of an emulsifier’s adsorption properties under conditions similar to those occurring during emulsion polymerization can provide important information to aid in the selection of the most appropriate surfactant for a given system. Results show that the latex particle size is dependent on the strength of emulsifier adsorption (∆Eads) at the particle/aqueous phase interface and is...

This Article describes a new microencapsulation method based on a Pickering emulsion templated interfacial atom transfer radical polymerization (PETI-ATRP). Cationic LUDOX CL nanoparticles were coated electrostatically with an anionic polymeric ATRP initiator, poly(sodium styrene sulfonate-co-2-(2-bromoisobutyryloxy)ethyl methacrylate) (PSB), prepared by radical copolymerization of sodium styre...

Abstract: In emulsion polymerization processes, the surfactant concentration plays an important role in the latex stability, reaction kinetics and particle size distribution (PSD). Controlling the free surfactant concentration in the aqueous phase ensures the stability of the latex and the control of the micellar nucleation rate. The PSD is determined by particle nucleation, growth and stabilit...

Superfine powders of poly (methyl methacrylate) (PMMA) have been prepared by means of an emulsion polymerization method. These have been used as templates in the synthesis of tetragonal phase mesoporous zirconia by the sol-gel method, using zirconium oxychloride and oxalic acid as raw materials. The products have been characterized by infrared spectroscopy, X-ray diffraction analysis, transmiss...