Design of Pressure-Sensitive Adhesives by Free-Radical Emulsion Copolymerization of Methyl Methacrylate and 2-Ethylhexyl Acrylate. 1. Kinetic Study and Tack Properties

Abstract

Pressure-sensitive adhesives must develop simultaneously two conflicting properties: adhesion and cohesion. To fulfill these requirements, it is imaginable to synthesize suitable materials by free-radical emulsion copolymerization of complementary monomers: methyl methacrylate (MMA) and 2-ethylhexyl acrylate (EHA). The copolymerization kinetics of various MMA/EHA mixtures is studied using a “batch” process. In all cases, the reaction proceeds at a steady-state rate and the copolymer composition (evaluated by 1H NMR analysis) is quite proportional to the conversion degree. The tack properties of films obtained by coalescence of the latexes are evaluated using a “mechano-optical tack tester”, which allows one to determine the tack strength (F tack), the tack energy (G tack), and the actual contact area (A) as functions of time. These tack properties are correlated with the copolymers and adhesive film structures.

Explanation of tackifier effect on the viscoelastic properties of polyolefin‐based pressure sensitive adhesives

“…2 Previous studies show that tackifiers increase the glass transition temperature but lower the plateau modulus of the base polymers. 2,4,6,18,21 This is very different from the effect of plasticizers or low molecular weight oils that decrease both the plateau modulus and the glass transition temperature of the systems. At the same time, tackifiers reduce the viscosity at low frequency rather than increase the viscosity as might be expected in the terminal zone 6 of the PSA systems.…”

“…Tackifiers improve the tack property of the base polymers by changing both their surface and bulk properties (viscoelastic properties). [2][3][4]6,10,18,20,21,24 Although the effects of tackifiers on the PSAs have been studied over the past four decades, a fundamental understanding of how tackifiers affect these properties is still incomplete. 3,4,14,18,24,25 The relationship between the viscoelastic properties and the tack property has been investigated.…”

“…[2][3][4]6,10,18,20,21,24 Although the effects of tackifiers on the PSAs have been studied over the past four decades, a fundamental understanding of how tackifiers affect these properties is still incomplete. 3,4,14,18,24,25 The relationship between the viscoelastic properties and the tack property has been investigated. 2,7,10,11,13,14,20,22,[27][28][29] Tackifiers act by bringing the viscoelastic state of the adhesive to one more state suitable to bonding and unbonding.…”

Deformation and adhesion of a periodic soft–soft nanocomposite designed with structured polymer colloid particles

“…Both tools have been previously used to design coatings or adhesives from latexes 8,19,20 , but the two have not been used in tandem to control nonlinear viscoelasticity, and well-defined structure-property relationships have not yet emerged.…”

Near-Surface Composition Profiles and the Adhesive Properties of Statistical Copolymer Films Being Model Systems of Pressure Sensitive Adhesive Films

“…With increasing acrylic acid content, the storage modulus and the loss modulus increased. In another investigation, Aymonier et al varied the methylmethacrylate (MMA) content in the statistical copolymer with PEHA (38). With decreasing MMA content, the tack energy increased up to a critical content of 25%.…”