Surface treatments styrene block copolymers

Upon examination of Figure 3 the butadiene homopolymer surface energy does not appear to be as strongly affected as the 25% styrene block copolymer. This realization alone would tend to discount the theory of styrene simply shielding ozone from the butadiene segments. The effect of ozone treatment on the change in surface energy appears to relate to the styrene content of the polymers studied. 

Figure 4. Effects of ozone exposure on critical surface energy of block copolymers and homopolymers as afunction ofbulk percent styrene content. Key to ozone treatment , untreated o, until chamber equilibrium +, 375 ppm for 75 min and , 375 ppm for 150 min.

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