title: Mechanical properties of a waterborne pressure-sensitive adhesive with a percolating poly(acrylic acid)-based diblock copolymer network: effect of pH.
abstract: Copolymerizing an acrylic acid comonomer is often beneficial for the adhesive properties of waterborne pressure-sensitive adhesives (PSAs). Here, we demonstrate a new strategy in which poly(acrylic acid) (PAA) is distributed as a percolating network within a PSA film formed from a polymer colloid. A diblock copolymer composed of PAA and poly(n-butyl acrylate) (PBA) blocks was synthesized using reversible addition-fragmentation chain transfer (RAFT) polymerization and adsorbed onto soft acrylic latex particles prior to their film formation. The thin adsorbed shells on the particles create a percolating network that raises the elastic modulus, creep resistance and tensile strength of the final film. When the film formation occurs at pH 10, ionomeric crosslinking occurs, and high tack adhesion is obtained in combination with high creep resistance. The results show that the addition of an amphiphilic PAA-b-PBA diblock copolymer (2.0 wt.%) to a soft latex provides a simple yet effective means of adjusting the mechanical and adhesive properties of the resulting composite film.
authors.affiliation: Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH, UK.
authors.forename: Robert S
authors.initials: RS
authors.lastname: Gurney
authors.affiliation: Department of Chemistry, University of Sheffield, Dainton Building, Brook Hill, Sheffield S3 7HF, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Morse
authors.affiliation: Allnex, Anderlecht Str. 33, B-1620 Drogenbos, Belgium.
authors.forename: Elodie
authors.initials: E
authors.lastname: Siband
authors.affiliation: Allnex, Anderlecht Str. 33, B-1620 Drogenbos, Belgium.
authors.forename: Damien
authors.initials: D
authors.lastname: Dupin
authors.affiliation: Department of Chemistry, University of Sheffield, Dainton Building, Brook Hill, Sheffield S3 7HF, UK.
authors.forename: Steven P
authors.initials: SP
authors.lastname: Armes
authors.affiliation: Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH, UK. Electronic address: j.keddie@surrey.ac.uk.
authors.forename: Joseph L
authors.initials: JL
authors.lastname: Keddie
keywords: Adhesion; Adsorption; Latex; Poly(acrylic acid) (PAA); Pressure-sensitive adhesive (PSA); Reversible addition–fragmentation chain transfer (RAFT); pH