Pressure sensitive adhesives (PSAs) are typically manufactured through exploratory mixing of polymers with various additives such as tackifiers and plasticizers to meet application specific requirements defined by tack stress, work of adhesion, bulk stiffness, and cohesive strength. These composite materials are difficult to fine-tune without changing chemical composition, which compounds the risk of low molecular weight compound leachability and property drift. Development of brush-like PSAs with precisely controlled network architecture overcomes these pitfalls by establishing viscoelastic control in one homogenous additive-free material. Herein, an <i>adhesion-by-architecture</i> approach to PSA engineering is examined. Polyisobutylene was utilized as a model brush-like elastomer system showing architecturally programmable adhesion behaviors empowered by the independent control over relaxation times and equilibrium modulus. Studies suggest this approach translates to a variety of chemistries including acrylate systems. This approach is advanced to the brush graft-copolymer platform demonstrating a combination of high tack and high cohesive strength. The graft copolymer bottlebrush architecture enhances the viscoelastic control to six independent architectural variables while physical crosslinks permit hot-melt preparation and molding. Furthermore, we establish direct structure property correlations between brush polymer architectures, viscoelasticity, and adhesion to cover a variety of PSA applications.

Encoding pressure sensitive adhesion in brush architecture

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.