Rational Design of Waterborne Polyurethane Pressure Sensitive Adhesives for Different Working Temperatures

Abstract

The appropriate pressure sensitive adhesion performances at working temperature are vital for the applications of waterborne polyurethane (WPU). Understanding the relationship among rheological behaviors, macromolecular structures and adhesive performances can be very useful to the rational design of waterborne polyurethane pressure sensitive adhesives (WPU-PSAs) for different operating temperatures, as well as other kinds of adhesives. In this study, four kinds of WPU-PSAs were prepared by reacting polypropylene glycol (PPG), hydrogenated hydroxyl-terminated polybutadiene (HHTPB), dimethyl alcohol propionic acid (DMPA), 1,6-hexamethylene diisocyanate (HDI) and four kinds of chain extenders. Gel permeation chromatography (GPC), swelling and rheology tests were used in parallel with an analysis of adhesive performances of the dried films of the adhesives. Results showed that, in addition to the nature of chain extenders playing a role on the rheological behaviors and adhesive performances of polymer, the gel content could be used to adjust the macromolecular structure and molecular weight distribution of polymer, thus distinctly affected the adhesive performances of PSA. The relationship among rheological behaviors, macromolecular structure and adhesive performances was investigated, and the rational design of WPU was achieved with appropriate pressure sensitive adhesion properties for different working temperatures of 25 and 60 °C.

A Humidity‐Insensitive Waterborne Polyurethane Pressure‐Sensitive Adhesive Modified by Castor Oil and Siloxane

“…[1] PSA is a class of viscoelastic material with both fluidity like a liquid and elasticity like a solid. [2] Viscidity enables the PSA to wet an adherend and to make close contact with the substrate for effective bonding. Moreover, an elastic component enables PSA to resist shear stress.…”

“…Pressure‐sensitive adhesive (PSA) can adhere to different kinds of surfaces under light external force in a short time, it is widely used in medicine, packaging, sticky notes and labels, and other fields [1] . PSA is a class of viscoelastic material with both fluidity like a liquid and elasticity like a solid [2] . Viscidity enables the PSA to wet an adherend and to make close contact with the substrate for effective bonding.…”

Strong Thermo-tolerant Silicone-Modified Waterborne Polyurethane/Polyimide Pressure-Sensitive Adhesive

“…Improving cross-linking and introducing thermo-tolerant substances are common ways to improve the heat resistance of pressure-sensitive adhesives. 15 Cross-linking can form a threesite network structure between linear polymer segments, limiting the relative motion of molecular chains and thereby improving the high temperature resistance. Cross-linking can be divided into physical cross-linking and chemical cross-linking.…”

Polymer Fractionation at an Interface in Simple Shear with Slip

“…The flow of polymer melts near surfaces is of considerable interest to both theorists and experimentalists. An understanding of the polymer’s behavior at the interface is essential in producing materials with desirable properties in various fields of research such as lubricants, coating, adhesives, and composite materials. − It also helps in suppressing processing-related problems such as die drool and melt fracture . This of course requires knowledge of the chain length distributions at the interface and the nature and type of the surface …”