1993 Volume 50 Issue 1 Pages 41-47
Poly (methyl methacrylate-co-methacrylic acid) -graft-polysiloxanes (PMAA-g-PDMSs) were prepared by radical copolymerization of methyl methacrylate (MMA), methacrylic acid (MAA), and silicone macromonomer (Si-MM). PMAA-g-PDMSs were treated with aqueous sodium hydroxide solution to give poly (methyl methacrylate-co-sodium methacrylate) -graft-polysiloxanes (PMAANa-g-PDMSs). Surface properties of coating films of copolymers having silicone branches (Mn=1000, 10000) were evaluated in terms of contact angle and dynamic coefficient of friction. From contact angle toward droplets of each solvent, the critical surface tensions (γc) were estimated by extrapolation to cos θ=1 and the solid surface tensions (γs) were evaluated by the extended Fowkes'equation. γcs were decreased from 32 dyn/cm to 22-24dyn/cm by the introduction of silicone segments. γs also decreased by the introduction of silicone segments; the values of each component (γsa, γsb, andγsc) were changed. The dynamic coefficient of friction decreased with neutralization of PMAA-g-PDMSs.
