The synthesis of nanosized poly(methyl methacrylate) initiated by 2,2′‐azoisobutyronitrile via differential microemulsion polymerization has been investigated. Poly(methyl methacrylate) with a molecular weight of around 1 × 106 and a particle size of about 20 nm was achieved under mild reaction conditions. A typical condition was that the surfactant amount required could be as low as 1/130 of the monomer amount in weight, and the surfactant/water ratio could be as low as 1/600, which is much less than the corresponding amounts reported in the literature. “Molecular bricks”, i.e., nanoparticles in which there are only one or two polymer chains, can be achieved using mild conditions by differential microemulsion polymerization, which may have potential applications for making molecular devices.magnified image

Cover: The cover picture describes a new approach which enables controllable formation of nano polymer particles. The resultant particles could contain only one or two polymer chains, i.e. they are molecular bricks with potential important applications. Further details can be found in the article by C. Norakankorn, Q. Pan,* G. L. Rempel,* and S. Kiatkamjornwong on page 1029.

No abstract

Nanosized poly(methyl methacrylate) (PMMA) particles with a high molecular weight of 10 6 g mol À1 and a polydispersity index of about 1-2 were synthesized, for which 2,2 0 -azobisisobutyronitrile was used as the initiator and a differential microemulsion polymerization technique was employed. The kinetics of the polymerization, the glass transition temperature, tacticity, the particle size distribution, and the morphology of the nanosized PMMA synthesized were investigated. The dependence of the number of the polymer particles (N p ) and the number of the micelles (N m ) on the concentration of the surfactant was discussed. The molecular weight distribution was found to be nearly constant over the polymerization time, which was attributed to the significance of micellar polymerization. The resultant nanosized PMMA has a rich syndiotactic configuration (53-57% rr triads) with a glass transition temperature of about 125 C. A beneficial operation condition was discovered where the conversion reached a maximum at a high monomer-to-water ratio.

Functionalized core/shell nanoparticles of the co-polymer of methyl methacrylate (MMA) and glycidyl methacrylate (GMA) could be polymerized by differential microemulsion polymerization, using a small amount of surfactant (the weight ratio of sodium dodecyl sulfate (SDS)/monomer is 1 : 24). The core/shell nanoparticles have a high conversion, high molecular weight, and small particle size (25-30 nm). The statistical analysis indicated that SDS, water, and the interactionbetween SDS and water have a significant positive interaction between the MMA conversion to form the core nanoparticles. For the core-shell polymer, [GMA]