Styrene copolymers, wettability

Okano, T., Katayama, M., and Shinohara, 1. The influence of hydrophobic and hydrophilic domains on water wettability of 2-hydrooxyethyl methacrylate/styrene copolymers, J. Appl. Polmer Sci, 1978, 22, 361-ill. 

The effects of improved wettability, entropic repulsion, and sterical hindrance undoubtedly play a role in stabilizing dispersed solid particles by block or graft copolymers. However, since the dispersions of titanium dioxide in toluene stabilized by carboxylated styrene-butadiene block copolymers are so much more stable than dispersions stabilized by carboxylated homopolymers under otherwise identical conditions, we must assume that an additional factor comes into play when block copolymers are used. The model in Figure 1 is an attempt to explain this additional... 

In a patent dated 1965 Stowe35) laid the basis for the copolymerization of PEO macromonomer with comonomers such as acrylonitrile. It was searched for an increased wettability of polyacrylonitrile films or fibers by a permanent surface modification. ro-Styryl poly(oxyethylene) macromonomers readily copolymerize with acrylonitrile in water emulsions. They can also be copolymerized with styrene-sulfonates in the presence of poly(vinylpyrrolidone). The presence of small amounts of such copolymers in polyacrylonitrile fibers was shown to increase their wettability and their receptivity to dyes and to make them more resistant to electric loading (antistatic fibers). No characterization data on the copolymers formed have been reported. 

Wettability of Elastomers and Copolymers. The wettability of elastomers (37, 38) in terms of critical surface tension was reported previously. The elastomers commonly used for the reinforcement of brittle polymers are polybutadiene, styrene-butadiene random and block copolymers, and butadiene-acrylonitrile rubber. Critical surface tensions for several typical elastomers are 31 dyne/cm. for "Diene rubber, 33 dyne/cm. for both GR-S1006 rubber and styrene-butadiene block copolymer (25 75) and 37 dyne/cm. for butadiene-acrylonitrile rubber, ( Paracril BJLT nitrile rubber). The copolymerization of butadiene with a relatively polar monomer—e.g., styrene or acrylonitrile—generally results in an increase in critical surface tension. The increase in polarity is also reflected in the increase in the solubility parameter (34,39, 40) and in the increase of glass temperature (40). We also noted a similar increase in critical surface tensions of styrene-acrylonitrile copolymers with the... 

Acrylic acid can be used as comonomer in different copolymers. The most common of these are probably poly(ethylene-co-acrylic acid) (see Section 6.1, Figure 6.1.7), poly(acrylic acid-co-acrylamide), and poly(acrylic acid-co-styrene-co-acrylonitrile) or ASA terpolymer. The acrylic acid in the poly(ethylene-co-acrylic acid) increases the wettability of the polymer. Different salts of poly(acrylic acid-co-acrylamide) are used in the water purification processes as water clarification aid and in drilling fluids. Additional -COOH groups make the polymer even more hydrophilic, and polymers such as poly(acrylic acid-co-maleic acid) are easily water soluble and used as liquid thickeners. 

Hikita, M., Tanaka, K., Nakamura, T. et al. (2004) Aggregation states and surface wettability in films of poly(styrene-block-perfluorooctyl ethyl acrylate) diblock copolymers synthesized by atom transfer radical polymerization. 

---