Polymethyl methacrylate latex

This molecule is a copolymer with polymethyl methacrylate (PMMA) in acrylic latex paints, where the hydrophobic PMMA is surrounded by hydrophilic polyvinyl acetate molecules. Such a suspension of a hydrophobic polymer wrapped in a hydrophilic polymer is called a latex. 

This paper compares the swelling of monodisperse polystyrene and polymethyl methacrylate latexes with their monomers and the estimated particle-water interfacial tensions with the theoretical curves from Morton s equation. A new model which takes into account the effect of water dissolved in the swollen particles and in the monomer phase on the swelling of relatively hydrophilic systems is presented. 

Swelling of polymethyl methacrylate latex particles with methyl methacrylate. Table IV lists the swelling ratios and interfacial tensions for the different-size polymethyl methacrylate latexes with added Aerosol MA and sodium dodecyl sulfate emulsifiers. Comparison of the data with the theoretical curves from Model I (Figure 2) defines an apparent interaction parameter of 0.45 and the semi-empirical equation ... 

In summary, the thermodynamic Model I based on Morton s theory has been used to successfully fit experimental data and obtain semi-empirical equations for the swelling of polystyrene and polymethyl methacrylate latexes. The semi-empirical equations offer a quick method for estimating swelling ratio from particle size and interfacial tension. The generalized form of Model II might prove to be more suitable for describing the swelling phenomena of relatively hydrophilic systems. ... 

Swelling of Polymethyl Methacrylate Latexes with Methyl Methacrylate in the Presence of Anionic Surfactants... 

Of course, it is impossible to find particles with zero adhesion to confirm the theoretical argument that spheres should form a face-centered cubic structure above 0.49 volume fraction. However, certain types of polymer latex can be made to approximate to the theoretical nonadhesion conditions above. Polymethyl methacrylate particles were polymerized in a dispersion and polymer molecules were grafted to the surface to provide a steep repulsive force on close approach. The solvent was chosen to reduce the van der Waals force to a low level, by matching the refractive index to the spheres, obtaining an almost transparent suspension from the milky preparation. 

Studies involving the use of organically modified clay particles in heterophase polymerization are rather scarce. Indeed, we are aware of only two reports that combine the emulsion or suspension polymerization approaches and ion-ex-change reaction. In one of these reports, AI BA is immobiHzed in the clay interlayer region to yield exfoliation of MMT in the PMMA matrix through suspension polymerization [135]. In another relevant study, it was demonstrated that exfoliated structures could be obtained by post-addition of an aqueous dispersion of layered silicates (either MMT or laponite) into a polymethyl methacrylate latex suspension produced in the presence of suitable cationic compounds (cationic initiator, monomer or surfactant) [136]. Since the latex particles were cationic and the clay platelets anionic, strong electrostatic forces were developed at the polymer/clay interface. 

The acrylics can be formulated as thermoplastic resins, thermosetting resins, and as a water emulsion latex. The resins are formed from polymers of acrylate esters, primarily polymethyl methacrylate and polyethyl acrylate. Since the acrylate resins do not contain tertiary hydrogens attached directly to the polymer backbone chain, they are esceptionally stable to oxygen and UV light. The repeating units for the methacrylate and acrylate are as follows ... 

Another graft copolymer that could be used for stabilization of suspensions is that based on polyfructose backbone on which several alkyl groups have been grafted (Inutec LiC 0.1), mentioned above for stabilization of emulsions. This polymeric surfactant was used to investigate the stability of polystyrene (PS) and polymethyl methacrylate (PMMA) suspensions in the presence of electrolytes [NaCl, CaCl2, and Al2(S04)3] [37]. Polystyrene latex... 

Cho and Lee [6] used three different initiators, potassium persulfate, 2,2 -azobisisobutyronitrile, and 4,4 -azobis(4-cyanovaleric acid) (water-soluble, but less hydrophilic than potassium persulfate) to investigate their effects on the emulsion polymerization of styrene in the presence of polymethyl methacrylate seed latex particles. Inverted core/shell latex particles were observed when 2,2 -azobisisobutyronitrile or 4,4 -azobis(4-cyanovaleric acid) was used to initiate free radical polymerization. The use of potassium persulfate resulted in various morphological structures of latex particles, which were largely determined by the initiator concentration and polymerization temperature. 

Effect of particle size (i.e., softness) on the low shear rate viscosity of suspensions containing sterically stabilized particles. Polymethyl methacrylate latex in decalin, stabilizer layer thickness, 9 nm particle diameters , 475 nm o, 376 nm , 129 nm and A, 84 nm. From D Haene (1991). 

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