Acids acrylic acid-coated filler

The same workers also examined the effects of the acrylic acidcoatings produced from acrylic add alone, but extensive grafting was found when peroxide was incorporated into the coating. 

A modified latex composition contains a phosphorus surface group. Such a latex is formed by emulsion polymerization of unsaturated synthetic monomers in the presence of a phosponate or a phosphate which is intimately bound to the surface of the latex. Thus, a modified latex containing 46% solids was prepared by emulsion polymerization of butadiene, styrene, acrylic acid-styrene seed latex, and a phosphonate comonomer in H20 in the presence of phosphated alkylphenol ethoxylate at 90°C. The modified latex is useful as a coating for substrates and as a binder in aqueous systems containing inorganic fillers employed in paper coatings, carpet backings, and wallboards [119]. 

Another attempt by Tricas et al. to modify the surface of carbon black was by the plasma polymerization of acrylic acid [34]. Treatment with acrylic acid made carbon black hydrophilic. Plasma-coated carbon black was mixed with natural rubber and showed increased filler-filler interaction. The bound rubber content was reduced after the surface treatment of the filler. The authors also concluded that the surface of the carbon black was completely covered by the plasma polymer film, preventing the carbon black surface from playing any role in the polymer matrix. 

Tabtiang and Venables [20] studied the reaction of acrylic acid with the surface of calcium carbonate. The coating was carried out by means of a dry method and their results again demonstrate the complexities that can be encountered. IR spectro-metric analysis of the coated fillers showed that all the acid was converted to the salt form, even when amounts well in excess of that required for a monolayer were used. However, the authors found no evidence of monolayer adsorption, with about half the added material becoming insoluble in xylene, a good solvent for calcium acrylate, at all levels of addition. They concluded that, with the method of coating employed, small droplets react with the filler to produce calcium acrylate, some of which is bound to the filler, or insolubilized in some way, while the rest remains as the free salt. 

Graft copolymers between unsatnrated acids, especially acrylic acid and maleic anhydride (MA), and polyolefins (PE and PP) are widely used as surface modifiers and compatibilisers, sometimes in combination with bi-functional coupling agents [46], for talc, calcium carbonate and calcined clays. Such polymer coatings include polypropylene-maleic anhydride [47], polypropylene c/s-4-cyclohexene-l,2 dicarboxylic acid [48], polystearyl or polylauryl acrylate [49], polypropylene-acrylic acid, partially oxidised poly(butane diol) [50] and ethylene-vinyl acetate copolymers [51]. Acid-containing products can react with basic fillers. With most other types, they will simply adsorb on to the mineral surface, but they can form esters with some non-basic metal hydroxyls, notably silanols. 

The presence of the acrylic acids in a copolymer may enhance the adhesion of the polymer to another substrate, particularly to a substrate such as aluminum, which is subject to corrosion by acids. Coatings containing methacrylic acid may have improved abrasion and wet- or dry-rub resistance. The hardness and the softening temperature may be increased because of the polarity conferred by these monomers. Pigments and fillers may be dispersed more readily in copolymers containing carboxylic acid... 

Maleic anhydride-co-acrylic acid grafted coatings for polyolefin fillers... 

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