Synthesis of PMMA/Polysiloxane Core-Shell Latex

In this study, silicon-acrylic latex, consisting of poly (methyl methacrylate) (PMMA) as the core and modified polysiloxane as the shell, had been successfully synthesized via cationic emulsion polymerization. The structure of the silicon-acrylic latex was confirmed by means of DLS, FTIR and TGA. There was an increase of 24.74 nm in average particle size and a shift of the size distribution to large sizes for core-shell particles in comparison with the original PMMA core particles, which indicated the formation of core-shell structure. The typical absorption peaks of Si-O-Si and Si-O-C in infrared spectrum indicated that the hydroxyl groups on the PMMA surface had reacted with the silanol groups, which could be confirmed by heterogeneous two-component system form TGA test

Effect of surfactant systems on the water sensitivity of latex films

The effects of three different types of surfactant systems (ionic, polymeric, and electrosteric stabilizers) on the water sensitivity of poly(butyl acrylate-co-methyl methacrylate) latex films was examined. The water sensitivity was found to be strongly dependent on the surfactant system used in their preparation. A number of factors, such as the surfactant mobility and crystallinity and surfactant/ polymer polarity appeared to affect the water uptake of the films. Highly mobile and crystallizable surfactants yielded high water sensitivity for films containing ionic surfactants, whereas the surfactant polarity had a greater effect on latices stabilized by polymeric surfactants, with the more hydrophilic systems providing greater water uptake. (C) 2004 Wiley Periodicals, Inc

Washing durability of cotton coated with a flourinated resin: an AFM, XPS and low frequency mechanical spectroscopy study

The evolution, during laundering, of mechanical, chemical, and morphological prop erties of cellulose fibers covered with a fluorocarbon resin is studied using a combination of low frequency mechanical spectroscopy (LFMS), x-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). From this study of the roughness and surface composition of the film covering cellulose fibers, new explanations are proposed for the decrease in water and oil repellency with washing, and its partial recovery with subsequent heat treatment such as ironing. The observed phenomena involve de-wetting and re wetting of the fluorinated polymer on the cellulose surfaces, inducing a modification of adhesion mechanisms between the fluorocarbon polymer and the cellulose fibers and the formation and/or destruction of fluorinated polymer bridges (matrix or ligand effect) between the fibers