Latex from polyacrylic acid

In the same year, Fulda and Tieke [75] reported on Langmuir films of monodisperse, 0.5-pm spherical polymer particles with hydrophobic polystyrene cores and hydrophilic shells containing polyacrylic acid or polyacrylamide. Measurement of ir-A curves and scanning electron microscopy (SEM) were used to determine the structure of the monolayers. In subsequent work, Fulda et al. [76] studied a variety of particles with different hydrophilic shells for their ability to form Langmuir films. Fulda and Tieke [77] investigated the influence of subphase conditions (pH, ionic strength) on monolayer formation of cationic and anionic particles as well as the structure of films made from bidisperse mixtures of anionic latex particles. 

PS latices were produced by dispersion polymerisation of the monomer in an ethanoFwater mixture. Polyacrylic acid, PVAl or polyvinyl pyrrolidone were used as steric stabilisers with a disperse-phase soluble initiator, i.e. AIBN. Transparencies of the films fonned from these PS latices were studied by measuring the transmitted photon intensities using a UV-visible spectrophotometer. Monte Carlo simulations were performed to calculate the transmitted photon intensities to simulate the latex fihn-formation process. The method developed by Prager and Tirrell was used to investigate the healing processes at the junction surfaces. 35 refs. 

The second important observation for the data in Figure 1 is that interdiffusion occurs even at the early stages of annealing time, in the all films. This result is very different from that reported by Joanicot et al. b for a different latex film. They found that polyacrylic acid [PAA] at the surface of a poly(styrene-co-butyl acrylate) latex effectively suppressed interdiffusion until the film temperature exceeded the Tg of the PAA, at which point the polar membranes ruptured. The essential difference in... 

However, when administered into the body, the particulate carriers are inevitably exposed to an attack firom the immune system, which protects the body from invasion by foreign products. Thus, injected particles are removed from blood via recognition by phagocytic cells [essentially macrophages located in the mononuclear phagocyte system (MPS), mainly in the liver and spleen]. For example, 50-90% of polystyrene latex particles disappear firom blood within the first five minutes after injection (Ilium et al, 1987). The same fate is observed in the case of particles made of other materials, such as poly(lactic acid) (PLA) (Bazile et al, 1992), polycyanoacrylate (Kreuter et al, 1979), polyacryl starch (Laakso et al, 1986), or albumin (Gottlieb ei a/., 1990). 

The number of resin emulsions and rubber latexes suitable for use as raw materials for adhesives is very large. Emulsions of homopolymers and copolymers of vinyl acetate are the most important. The comonomers for vinyl acetate include maleic esters, acrylates, ethylene and vinyl chloride, unsaturated carboxylic acids, and vinyl esters of relatively long-chain fatty acids, such as vinyl laurate. Apart from these products, polyacrylate homopolymers and copolymers and also styrene copolymers are particularly important in adhesives [42]. 

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