Surface segregation of polydimethylsiloxane-polyether block copolymers in coatings driven by molecular architecture

Abstract Block copolymers containing polydimethylsiloxane (PDMS) and poly(ethylene oxide) (PEO) or poly(propylene (PPO) with varying molar masses were synthesized in a three-step pathway. The functional homopolymer blocks final diblock characterised using proton Nuclear Magnetic Resonance (1H NMR) Matrix Assisted Laser Desorption/Ionization Time of Flight Mass Spectroscopy (MALDI-ToF-MS). These polymers then incorporated an industrially relevant solvent-borne coating formulation. Using X-ray Photoelectron (XPS) combination angle-resolved depth profiling measurements, concentration profiles the block copolymer top few nanometres cured obtained. amphiphilic molecules found to be extremely surface active, high levels PDMS enrichment observed at only minimal concentrations. extent segregation is sensitive exact mass both siloxane polyether block, where increase size either part resulted overall decrease enrichment. PDMS-PPO was more compatible network than PDMS-PEO, as evidenced by substantial lower former. properties liquid films additionally tension water contact angle which largely confirmed trends XPS. characterisation complex dynamic processes occurring during drying key provide ability effectively tune specific systems for required individual applications.