Views: 0 Author: Site Editor Publish Time: 2025-08-04 Origin: Site
Hydrolysis is a common and damaging problem in acid-containing reactant systems. When moisture interacts with acidic groups within polymers, it triggers chemical reactions that break down molecular chains. This degradation reduces material strength, causes cracking, and leads to early product failure. Industries relying on adhesives, coatings, inks, and sealants frequently face these challenges, especially in humid or high-temperature environments. Finding effective ways to protect these materials from hydrolysis is critical for ensuring long-term reliability and performance.
In today’s industrial landscape, many high-performance formulations rely on acid substance reactants to achieve desired chemical properties. These systems typically contain functional groups such as carboxyl (–COOH), phosphoric (–PO₄H₂), or sulfuric (–SO₃H) groups that are essential to the polymer’s functionality or curing mechanism.
Common examples include adhesives, coatings, inks, sealants, and certain specialty polymers or elastomers. Whether it’s a polyurethane adhesive with residual carboxyl groups, a polyester coating, or an ink formulation that needs controlled acidity for pigment dispersion, these systems frequently depend on acid-containing reactants to achieve performance targets.
However, this very feature also becomes a major weakness. Acid-reactant systems are particularly vulnerable to hydrolysis, a process where water—often combined with inherent acidity and environmental heat—breaks down the polymer’s molecular chains over time. This degradation directly shortens the lifespan of the product, leading to early failures, costly replacements, and damage to brand reputation.
As markets increasingly demand durable, long-lasting materials that perform reliably even in challenging environments, manufacturers and formulators are under pressure to prolong the service life of their products. This is where anti-hydrolysis agents become indispensable. These specialized additives are engineered to protect polymers from the destructive effects of water and acids, extending product lifespan, maintaining critical properties, and ultimately saving costs throughout the value chain.
Hydrolysis is a chemical reaction where water molecules attack the sensitive bonds within polymers—particularly ester, amide, or urethane linkages. In acid-containing systems, this process is often catalyzed by the acidic groups already present in the formulation, accelerating the breakdown.
For example:
Carboxyl acids (–COOH) can catalyze the hydrolysis of esters, leading to chain scission.
Phosphoric or sulfuric groups may similarly destabilize adjacent polymer linkages.
Heat and humidity exacerbate these reactions, increasing the rate of molecular weight drop.
When hydrolysis progresses in an acid-reactant formulation, several visible and mechanical failures follow:
Loss of molecular weight: Polymer chains break into shorter fragments, losing cohesive strength.
Embrittlement: Materials that once had excellent flexibility or elongation become stiff and prone to cracking.
Surface cracking or crazing: The first sign of hydrolysis often appears as small surface cracks, especially under mechanical stress.
Delamination: In layered systems like films or laminates, adhesion fails, causing layers to peel or blister.
These issues become even more severe in warm, humid environments, such as tropical regions or industrial plants with high moisture loads.
The primary function of anti-hydrolysis agents is to prevent the cleavage of polymer chains caused by the combined attack of water and acids. By reacting with acidic end groups, these stabilizers reduce the availability of catalytic sites where hydrolysis typically initiates. This stabilizes the polymer backbone and prevents molecular weight loss, which is critical for maintaining strength and durability.
By protecting polymer chains, anti-hydrolysis agents help retain:
Mechanical strength: Tensile strength and impact resistance remain high over extended periods.
Elasticity and flexibility: The polymer avoids embrittlement and cracking, preserving its functional performance.
Adhesion: In adhesive and sealant systems, bond strength does not degrade prematurely.
Appearance: Hydrolysis often causes yellowing, chalking, or surface degradation, which these agents help minimize.
Typical improvements observed with effective anti-hydrolysis agents include:
Retained tensile strength: Often over 90% retention after prolonged hot water or humid aging tests.
Maintained elongation at break: Ensures materials don’t become brittle.
Stable peel or shear adhesion: Crucial for coatings and adhesives exposed to moisture.
Many adhesive formulations, particularly those based on polyurethane, polyester, and epoxy systems, inherently contain residual acid groups derived from their monomers or curing agents. These acid groups can inadvertently catalyze hydrolysis, especially when the adhesive is exposed to humid or chemically aggressive environments. Over time, this can lead to premature degradation or complete failure of bonded joints. By strategically incorporating anti-hydrolysis agents into these formulations, manufacturers can markedly extend the lifespan and reliability of adhesive bonds. This enhancement is especially critical in demanding applications such as automotive weather seals, structural construction adhesives, and electronic encapsulants where a failure could result in costly repairs, safety hazards, or significant operational downtime.
Coatings and inks frequently rely on acid-containing acrylic or polyester resins to achieve optimal film formation, pigment dispersion, and surface adhesion. However, these acid-functionalized resins are inherently vulnerable to hydrolysis, which often manifests as surface defects like cracking, chalking, or a gradual loss of gloss and color integrity. The introduction of anti-hydrolysis agents serves to protect the integrity of the resin matrix, ensuring that coatings remain flexible, durable, and visually appealing over extended periods. This protection is especially important under continuous exposure to moisture, frequent washing, or harsh industrial cleaning agents that would otherwise accelerate degradation.
Certain specialty polymers, including engineered polyesters and polyamides, are intentionally synthesized with acidic monomers to achieve tailored performance characteristics such as chemical resistance or thermal stability. Similarly, elastomers like specific polyurethane rubbers contain acid-reactive sites within their molecular structure. Without adequate stabilization, these materials can lose their toughness, elasticity, and resistance to mechanical stress. Employing anti-hydrolysis agents is therefore essential to preserve their functional properties, particularly in high-demand applications such as industrial rollers, dynamic seals, or automotive components that are routinely exposed to moisture, fluctuating temperatures, or mechanical abrasion.
Anti-hydrolysis agents are typically added during the compounding or mixing stage of resin formulation. This ensures thorough dispersion and intimate contact with polymer chains and acid groups.
Forms: These stabilizers come in liquid or solid (powder or masterbatch) forms. Liquid polycarbodiimides offer easier dosing and uniform distribution, while powders may be preferred for certain processing methods.
Dosage: The typical range is 0.5% to 2.0% by weight relative to the total polymer content. Dosage selection depends on acid content, expected exposure conditions, and product lifespan goals.
When incorporating anti-hydrolysis agents, it’s important to verify compatibility with other formulation components such as:
Catalysts
Pigments and dyes
Fillers and reinforcements
Flame retardants
Proper compatibility testing helps avoid unintended side reactions or changes in processing behavior.
Hydrolysis poses a serious threat to acid-containing reactant systems, where acidity and moisture cause polymer degradation, leading to cracking, embrittlement, and loss of performance. Advanced anti-hydrolysis agents, especially polycarbodiimide-based stabilizers, effectively protect polymers by neutralizing acidic groups and blocking hydrolysis reactions, helping to prolong service life. This significantly extends the lifespan of adhesives, coatings, inks, sealants, and specialty polymers.
For manufacturers aiming to produce durable products that perform well in humid, hot, or harsh chemical environments, using the right anti-hydrolysis agents is crucial. These additives improve product longevity, reduce failures, and lower warranty costs.
To learn more about tailored hydrolysis solutions and find expert support, consider contacting Suzhou Ke Sheng Tong New Materials Technology Co., Ltd. They specialize in advanced polymer additives and can help you enhance durability and product quality. Visit their website or reach out to their team for more information.
