Surface modification of poly(phenylene sulfide) using photoinitiated chlorine dioxide radical as an oxidant

Poly(phenylene sulfide) (PPS), a high-performance engineering plastic, possesses many desirable characteristics, such as outstanding high-temperature stability, inherent flame resistance, and excellent mechanical properties. Owing to its excellent chemical resistance, the modification of PPS for further applications, such as printed circuit boards (PCBs), is difficult. In this study, a photoinitiated chlorine dioxide radical (ClO2•) was utilized as an oxidant to modify the PPS film surface to improve its hydrophilicity and adhesion properties with different metals. IR and XPS analyses confirmed that oxygen-containing groups are introduced onto the PPS film surface, and its hydrophilicity is improved. Electroless plating was performed to deposit Cu and Ni metals onto the PPS surface, and the strength of adhesion between the polymer and metals was evaluated using a tape test. This novel modification method can be successfully utilized as a pretreatment for electroless plating, showing great potential for application in flexible printed circuits and the automotive industry in the future. Surface oxidation method using chlorine dioxide radical (ClO2•) for poly(phenylene sulfide) (PPS) was developed. During the oxidation reaction, sulfonyl groups and sulfite groups were successfully introduced to the surface of the PPS films. The water contact angle of the surface of the PPS film decreased dramatically after the oxidation, indicating that the surface hydrophilicity was improved. Electroless plating demonstrates that typical metals could be tightly deposited on the surface of oxidized PPS film and cannot be removed. This method provides an effective, clean, energy-saving treatment for super engineering plastics.