Amphiphilic Poly(Phenylene Sulfide)-Poly(Vinyl Catechol) Block Copolymers Enabling Hydrophobic/Hydrophilic Adhesion

Poly(1,4-phenylene sulfide) (PPS) is a super-engineering plastic with a low weight and excellent thermostability for automobile and electronic applications. However, it exhibits poor adhesiveness and compatibility with other materials owing to its low polar and semicrystalline nature with strong π-π intermolecular interactions. In this study, we demonstrate that an amphiphilic block copolymer, composed of hydrophobic poly(2,6-dimethyl-1,4-phenylene sulfide) (PMPS) and hydrophilic poly(4-vinylcatechol) (PVCa), can serve as an adhesive for PPS without any physical or chemical surface treatment. The key molecular design lies in the exceptional miscibility of PMPS with both the crystalline and amorphous domains of PPS, which enables their robust adhesion just by film coating and heating (fracture strength > 2.0 MPa). Furthermore, the block copolymer exhibits a high adhesive strength (over 1.0 MPa) to hydrophilic substrates, such as glass, stainless steel, and copper, which is attributed to its compatibility with both hydrophobic and hydrophilic surfaces. Overall, this study provides a rational design for polymer adhesives enabling similar/dissimilar material bonding of hydrophobic and less-adhesive super-engineering plastics without surface modification.