Adhesives: The application of texture analysis on the latest developments

The focus for the adhesive industry is the creation of a new generation of adhesives based on cutting-edge technologies including nanotechnology, derivatised polymers, and biomimetic adhesives. Because of the scarcity of raw materials and the harmful impact of synthetic adhesives on human health and the environment, more research into renewable materials is needed to develop environmentally friendly bioadhesives that best fit their application. Smart adhesives, such as switchable types which can be triggered to bond and de‐bond in response to physical or chemical stimuli are under development and some are already available commercially. These will contribute to product disassembly and recycling.

In order to do this, formulation and processing parameters will need to be assessed to check which variations produce the most optimum end result. Once the desired physical properties, are achieved a Texture Analyser can then be employed to measure and control the quality of the product and ensure manufacturing consistency is maintained.

As with any manufacturing innovation, a large amount of research takes place during development, and the end product must go through a quality control process to assess its physical properties. Novel adhesive examples being researched include the development of an insect proof starch adhesive to inhibit larvae infestation, eco-friendly denture adhesives (PDF) and the development of adhesive material from consumer waste polystyrene.

What are the new material and product ideas in adhesives research, development and production and how can a Texture Analyser be applied?

Adhesives play a pivotal role in various industries, including construction, automotive, packaging, and electronics. Research and development in this field often focus on improving performance characteristics, environmental sustainability, and safety. Here are some of the newer ingredient and product ideas in adhesive research, development, and production and a typical academic reference to show how the Texture Analyser has already being applied:

Bio-based adhesives: Made from renewable resources, such as plant-based polymers or proteins, these aim to reduce the carbon footprint and dependency on petroleum-based ingredients.
Example: A novel bioactive polyurethane with controlled degradation and L-Arg release used as strong adhesive tissue patch for hemostasis and promoting wound healing
Waterborne adhesives: These formulations replace solvents with water, reducing VOC emissions and improving workplace safety.
Example: Optimisation of adhesive performance of waterborne poly (urethane-urea) s for adhesion on high and low surface energy surfaces
Pressure-sensitive adhesives (PSAs): Advanced adhesives that don't require heat, water, or pressure to bond, useful in labels, tapes, and other applications.
Example: Development of cardanol-derived epoxidized and Si-modified pressure-sensitive adhesives (PSAs)
Reactive adhesives: These formulations undergo chemical reactions (often involving moisture or UV light) to bond surfaces. Adhesives that can change properties in response to external stimuli, such as temperature, light, or pH.
Example: Photoresponsive, switchable, pressure-sensitive adhesives: influence of UV intensity and hydrocarbon chain length of low molecular weight azobenzene compounds
Recyclable adhesives: Designed to enable easier recycling of products by allowing for the adhesive to be separated from substrates.
Example: 3D Printing of Recyclable Elastomers with Controllable Degradation and Adhesive Properties
Thermal management adhesives: Designed to conduct or insulate heat in applications like electronic devices.
Example: Aero-and thermodynamical optimisation of cooling tunnels for chocolate systems
Self-healing adhesives: Inspired by natural systems, these adhesives can "heal" or revert to their original state after being damaged.
Example: Multi‐Crosslinked Hydrogels with Instant Self‐Healing and Tissue Adhesive Properties for Biomedical Applications
Green and sustainable adhesives: Adhesives formulated to be eco-friendly, reducing VOC emissions, and with degradable or recyclable properties.
Example: Sustainable panels based on starch bioadhesives: An insight into structural and tribological performance
Conductive adhesives: Infused with conductive materials like silver or carbon, these are used in electronic assemblies and devices.
Example: Highly Stretchable, Self-Repairable, and Super-Adhesive Multifunctional Ionogel for a Flexible Wearable Sensor
Medical adhesives: Adhesives designed for medical applications like wound care, medical device attachment, or drug delivery, with biocompatible and often bioresorbable properties.
Example: In situ gelling mucoadhesive eye drops: evaluation of physicochemical properties, in vitro dissolution and transcorneal permeability
High-performance structural adhesives: Adhesives capable of bonding dissimilar materials like metals and composites with high durability and resistance to environmental factors.
Reversible or repositionable adhesives: Adhesives that can be easily removed or repositioned without leaving residue or damaging surfaces, useful in applications like labels or temporary fixtures.
UV-curable adhesives: Adhesives that harden or set when exposed to UV light, offering fast curing times and reduced energy consumption.
Nanotechnology-enhanced adhesives: Incorporation of nanoparticles to improve adhesive properties such as toughness, thermal stability, or electrical conductivity.
Adhesives for extreme conditions: Formulations designed to withstand extreme temperatures, pressures, or aggressive chemicals, suitable for aerospace, deep-sea, or heavy industrial applications.
3D printing adhesives: Formulations suitable for 3D printing technologies, allowing for custom adhesive structures or patterns.
Hot melt adhesives: They're solid at room temperature but melt when heated, allowing for quick setting and bonding.

The continuous evolution in the world of adhesives is driven by the need to meet the dynamic demands of industries ranging from electronics to healthcare, aerospace to consumer goods, and beyond.

Using a Texture Analyser in adhesive development

The integration of Texture Analysers in adhesives product research and development (R&D) presents a multifaceted approach to comprehending adhesive properties, which are integral to a wide range of applications. Peel strength measurement, pivotal for products like tapes and labels, gauges the force needed to peel an adhesive from a substrate. The assessment of tack delves into the initial stickiness of an adhesive, particularly pertinent for Pressure Sensitive Adhesives (PSAs). Shear strength evaluation determines an adhesive's resistance against internal sliding forces, while cohesive strength measurement quantifies its internal robustness and resistance to separation. Elasticity analysis is essential for flexible adhesives, offering insights into their deformation under stress and subsequent return to original states. Although viscosity assessment is often carried out by rheometers, Texture Analysers provide indications about adhesive flow and spread under specific conditions. Creep resistance monitoring observes adhesive behaviour under constant loads over time, contributing to understanding long-term performance. Durability tests explore adhesive behaviour across diverse environmental conditions, including humidity and temperature variations.

Texture Analysers are also relevant for assessing hardness, especially for hot melt adhesives or solid-state formulations, while determining setting time offers insights into the adhesive's speed of achieving final strength. These analyses, combined with other testing methods, offer a comprehensive grasp of adhesive performance. The insights derived from such evaluations guide formulation refinements, ensuring adhesives align with specific application performance criteria. In the realm of adhesive product R&D, Texture Analysers play a pivotal role, facilitating meticulous analysis and contributing to the development of adhesives tailored for diverse needs. Texture Analysers, combined with other testing methods, can offer a comprehensive understanding of adhesive performance. Such insights guide formulation adjustments, ensuring adhesives meet the desired performance criteria for specific applications.