Solve adhesion failures with the right polyols for adhesives
From automotive to construction, poor adhesion shortens product lifespans and compromises structural integrity, safety, and reputation.
Environmental stressors, including moisture, UV rays, and extreme temperatures, are tied to adhesive failures, prompting manufacturers to re-evaluate formulations for longevity.
The difference between adhesion that fails or endures often lies in one critical formulation building block: polyols.
Explore how strategically selecting polyols for adhesives can elevate performance in today’s most demanding applications.
Why moisture still wrecks adhesive performance
Without a proper moisture barrier, adhesives can lose strength, suffer from hydrolysis, and ultimately fail at the joint.1
Moisture intrusion remains a leading cause of adhesive degradation across industries, but the consequences vary by application:
| Sector | Moisture impact |
| Packaging | Causes delamination and shortens packaging life, compromising product safety. 2 3 |
| Footwear | Exposure to rain, water, or sweat can cause adhesives to peel. 4 |
| Construction | Moisture exposure undermines the structural integrity of construction-based adhesives. 5 |
| Automotive | Accelerates degradation of adhesive bonds, impacting performance and durability. 6 |
How polyols help mitigate moisture challenges
Due to their hydrophobic nature, polyether polyols, like Shell CARADOL®, offer superior moisture resistance. They repel water rather than absorb it, making them ideal for indoor and outdoor applications where adhesives must perform under variable conditions. 7 8 9
Polyether polyols are less prone to hydrolysis, making them a strategic building block in formulas for moist environments. 10
Looking to explore more strategies for high-performance adhesion? Download Making it Stick.
How UV exposure compromises adhesives
Without UV-resistance, adhesives are prone to discolouration and physical degradation, compromising product quality and lifespan.
UV exposure affects adhesives differently depending on the application:
| Sector | UV impact |
| Packaging | Causes discolouration and reduces joint strength, impacting shelf appeal. 11 |
| Footwear | Creates adverse cosmetic effects and physical alterations, affecting product durability. 12 |
| Construction | Photodegradation breaks polymer bonds, leading to property loss and discolouration. 13 |
| Automotive | Prolonged exposure creates cracking and discolouration. 14 |
How stabilisers help mitigate UV challenges
Polyether polyols can be formulated with UV stabilisers to counteract discolouration. 15 While inherently sensitive to UV radiation, polyether-based adhesives for outdoor use often include stabilisers and fillers to block or absorb harmful rays.
Additionally, polyether polyols offer greater flexibility, helping maintain bond integrity and can reduce cracking from prolonged UV exposure. 16
How polyols improve adhesive temperature performance
Extreme heat or cold can impact adhesive durability and reliability without strategic polyol selection.
Temperature affects adhesives differently across industries:
| Sector | Temperature impact |
| Packaging | High heat can soften bonds, while cold can cause brittleness. 17 |
| Footwear | Adhesives soften in high temperatures and lose flexibility in cold, leading to cracking. 18 |
| Construction | Exposure to extreme temperatures can degrade adhesives in flooring and structural use. 19 |
| Automotive | Thermal expansion and contraction reduce bond strength, risking failure. 20 |
How polyols help mitigate temperature challenges
Polyether polyols offer improved flexibility and excellent low and high-temperature performance. 21 22 23 Their cold-weather resilience can prevent brittleness, while their high-heat resistance supports durability. 24
Due to their more flexible ether bonds, polyether polyols can enable better performance in cold environments.25 This makes them ideal for adhesives used in outdoor and all-weather applications.
Common bond failures formulators face
In addition to environmental stressors, formulators often face three core bond failure types: adhesive, cohesion, and substrate failure. Each presents unique challenges that polyol selection can help address.
| Failure type | What happens | Common causes |
| Adhesive | The adhesive fails to bond to one or both surfaces. | Poor surface preparation, low application temperature, insufficient wetting, or incompatibility. |
| Cohesion | The adhesive splits within itself, not at the substrate. | Inadequate curing, contamination, or improper preparation. |
| Substrate | The bonded material itself breaks. | The adhesive bond is stronger than the substrate, a desired result unless debonding is needed. |
How polyols help mitigate failures
Polyether polyols offer lower viscosity and have better wetting characteristics, improving surface adhesion. This can help reduce the likelihood of adhesive failure, especially on complex surfaces.
Additionally, polyether-based polyurethane (PU) adhesives are often easier to process, which can help formulators achieve more consistent application, better cure profiles, and stronger overall bond integrity.
Strengthen performance with polyether polyols for adhesives
Adhesive manufacturers can overcome common environmental and bonding challenges by selecting the right polyol for the formulation.
Polyether polyols can help enhance performance in critical areas, including:
- Water resistance
- UV stability
- Temperature durability (hot and cold)
- Adhesion strength
- Bond reliability
Environmental stressors and bond failures don’t have to limit adhesive performance. With Shell CARADOL polyether polyols, manufacturers can develop adhesives that last across industries, climates, and materials.
Explore our brochure to discover polyol solutions tailored to your application, or speak to an expert to find the right Shell CARADOL polyol for your formulation needs.
Related resources:
How to propel polyurethane footwear formulas forward
Driving comfort and durability: How polyether polyols are shaping the cars of tomorrow
Sources
1 https://adhesives.specialchem.com/tech-library/article/improving-the-moisture-resistance-of-adhesives-and-sealants-part-ii
2 https://link.springer.com/chapter/10.1007/0-387-32989-7_37
3 https://adhesives.org/markets/paperboard-packaging/
4 https://journals.sagepub.com/doi/10.1177/1464420715602441?icid=int.sj-full-text.similar-articles.1
5 https://adhesives.org/markets/building-construction/
6 https://www.sciencegate.app/document/10.1177/0954406220944208
7 https://pubs.acs.org/doi/pdf/10.1021/bk-2021-1399.ch001
8 https://adhesives.specialchem.com/tech-library/article/improving-the-moisture-resistance-of-adhesives-and-sealants-part-ii
9 https://www.sciencedirect.com/science/article/abs/pii/S0079670018302995
10 https://pubs.acs.org/doi/pdf/10.1021/acssuschemeng.1c02558
11 https://adhesives.specialchem.com/selection-guide/uv-light-stabilizers-state-of-the-art
12 https://adhesives.specialchem.com/selection-guide/uv-light-stabilizers-state-of-the-art
13 https://adhesives.specialchem.com/selection-guide/uv-light-stabilizers-state-of-the-art
14 https://adhesives.specialchem.com/selection-guide/uv-light-stabilizers-state-of-the-art
15 https://pmc.ncbi.nlm.nih.gov/articles/PMC11085269/
16 https://www.sciencedirect.com/science/article/pii/S2542504820300269
17 https://www.sciencedirect.com/science/article/abs/pii/S1359836818316184
18 https://www.sciencedirect.com/science/article/abs/pii/S1359836818316184
19 https://adhesives.org/markets/building-construction/
20 https://www.researchgate.net/profile/M-Banea/publication/245389867_The_effect_of_temperature_on_the_mechanical_properties_of_adhesives_for_the_automotive_industry/links/54983df90cf2519f5a1dda97/The-effect-of-temperature-on-the-mechanical-properties-of-adhesives-for-the-automotive-industry.pdf
21 https://pubs.acs.org/doi/pdf/10.1021/acssuschemeng.1c02558
22 https://www.google.com/books/edition/Handbook_on_Modern_Packaging_Industries/3i8XDAAAQBAJ?hl=en&gbpv=1&dq=polyether+polyols+high+and+low+%22temperature%22+resistance,+cold+and+heat&pg=PA12&printsec=frontcover
23 https://link.springer.com/article/10.1007/s13233-020-8138-5
24 https://adhesives.specialchem.com/selection-guide/polyurethane-resins
25 https://www.mdpi.com/2079-6412/15/1/61