Tailoring Pressure Sensitive Adhesives with H₆XDI‐PEG Diacrylate for Strong Adhesive Strength and Rapid Strain Recovery

Abstract

The development of flexible electronic technology has led to convenient devices, including foldable displays, wearable, e‐skin, and medical devices, increasing the need for flexible adhesives that can quickly recover their shape while connecting the components of the device. Conventional pressure sensitive adhesives (PSAs) can improve recoverability via crosslinking, but often have poor adhesive strength. In this study, new types of urethane‐based crosslinkers are synthesized using m‐xylylene diisocyanate (XDI) or 1,3‐bis(isocyanatomethyl)cyclohexane (H6XDI) as a hard segment, and poly(ethylene glycol) (PEG) group as a soft segment. The PSA with the synthesized H6XDI‐PEG diacrylate (HPD) demonstrates a significantly improved recoverability compared to XDI‐PEG diacrylate and a conventional crosslinker 1,6‐hexanediol diacrylate (HDDA) while maintaining high adhesion strength (≈25.5 N 25 mm−1). The excellent recovery property of the PSA crosslinked with HPD is further confirmed by 100k folding tests and 10k multi‐directional stretching tests exhibiting high folding and stretching stability. PSA with HPD also shows high optical transmittance (> 90%) even after 20% straining, suggesting its applicability in fields that simultaneously require high flexibility, recoverability, and optical clarity such as foldable displays.

Sustainable and Renewable Microcross-Linked Polyurethane Pressure-Sensitive Adhesive from Waste Polyethylene Terephthalate

“…(F) Viscosity of GPUA as a function of temperature. (G) Comparison of shear strength of other reported pressure-sensitive adhesives. − …”

Styrenic Block Copolymer-Based Pressure Sensitive Adhesives without Volatile Compounds Using Organic Eutectic Liquid

“…Pressure sensitive adhesives (PSAs) can rapidly adhere to surfaces at room temperature with the application of a low pressure. − This feature distinguishes PSAs from other types of adhesives, such as liquid glues that solidify after a chemical reaction or hot-melt adhesives that become tacky when melted and then harden upon cooling to room temperature . Owing to their ease of use and ability to rapidly adhere to a wide range of substrates, PSAs are commonly used in various applications, including tapes, labels, stickers, and medical dressings. − The global market for PSAs exceeded USD 8.3 billion in 2022 and is projected to achieve a compound annual growth rate of 6% over the next decade, which is attributed to the increasing utilization of tapes and labels in automotive and transportation applications. , For example, PSAs are extensively used in various automobile parts, such as the exterior and interior trim, bonnet, and body. They can improve vibration and noise-damping properties without significantly increasing the weight of the vehicle.…”