Views: 0 Author: Site Editor Publish Time: 2025-06-16 Origin: Site
Crosslinking agents play a crucial role in modern materials science by chemically connecting polymer chains or molecules, enhancing the performance and durability of various products. Among them, anti-hydrolysis crosslinking agents have gained significant attention for their ability to protect materials from moisture-induced degradation, extending product life in harsh environments. This article explores the diverse uses of crosslinking agents, with a special focus on anti-hydrolysis types, their mechanisms, and applications across industries.
A crosslinking agent is a chemical substance that facilitates the formation of covalent bonds between polymer chains or molecules, creating a three-dimensional net
work structure. This bonding significantly alters the physical properties of materials, improving mechanical strength, thermal stability, chemical resistance, and elasticity.
Common crosslinkers include sulfur (widely used in rubber vulcanization), peroxides, silanes, and specialized agents like carbodiimides. These agents are selected based on the desired performance characteristics and application environment.
An anti-hydrolysis crosslinking agentis a specialized type of crosslinker designed to resist degradation caused by moisture or water. Hydrolysis can break down polymer chains, weakening materials over time. Anti-hydrolysis agents protect polymers by forming robust chemical bonds less susceptible to water attack, making them ideal for use in humid or wet conditions.
Crosslinking improves several critical properties of polymers:
Improving tensile strength and structural integrity
Enhancing resistance to heat and chemicals
Increasing elasticity and dimensional stability
Hydrolysis is a chemical reaction with water that can cleave polymer bonds, resulting in material breakdown. This is particularly problematic for applications exposed to moisture or water over long periods, such as automotive parts, outdoor coatings, and medical devices.
Anti-hydrolysis crosslinking agents combat this by forming bonds that are stable in moist environments, greatly enhancing material longevity and reliability.
Crosslinking agents find use in a wide range of industries. Below is a summary of the most common application areas with examples.
| Application Area | Use of Crosslinking Agent | Role of Anti-Hydrolysis Agent |
|---|---|---|
| Plastics & Thermoplastics | Improve heat resistance, flame retardancy, solvent resistance (e.g., polyethylene, EVA) | Protects cables and plastic components from moisture-induced breakdown |
| Rubber & Elastomers | Vulcanization with sulfur or peroxides to improve elasticity and durability | Increases rubber lifespan under humid conditions (tires, seals) |
| Coatings & Paints | Enhance durability, adhesion, weather resistance | Prevents water damage in marine and outdoor coatings |
| Adhesives & Sealants | Improves bonding strength, thermal and chemical resistance | Ensures adhesive integrity in damp or wet environments |
| Composites & Fiberglass | Strengthens fiber-matrix bonds, enhances mechanical properties | Extends service life of composite materials exposed to moisture |
| Medical & Cosmetic | Crosslinked hyaluronic acid in dermal fillers for longer-lasting effects | Increases stability of fillers in the body, reducing degradation |
Crosslinkers like dicumyl peroxide (DCP) and radiation-activated agents are widely used to improve the heat resistance, strength, and flame retardancy of plastics such as polyethylene, EVA, and chlorinated polyethylene. The addition of anti-hydrolysis agents enhances the material's resistance to moisture, preventing premature aging and failure in applications like cable insulation.
Sulfur-based crosslinkers remain the dominant agents for rubber vulcanization, creating flexible yet strong materials used in tires, seals, and hoses. For specialized rubbers such as ethylene propylene or fluorine rubbers, peroxides and anti-hydrolysis agents help accelerate curing and improve resistance to solvents, wear, and moisture.
In coatings, crosslinking agents enhance durability, UV resistance, and chemical protection. Anti-hydrolysis crosslinkers play a vital role in marine paints and outdoor coatings, where exposure to water can cause peeling and degradation. Similarly, adhesives benefit from crosslinkers that ensure stable bonding under varying humidity levels.
Crosslinked hyaluronic acid fillers rely on agents like BDDE (1,4-butanediol diglycidyl ether) and DVS (1,4-divinylbenzene) to transform liquid hyaluronic acid into a gel with prolonged stability inside the human body. Anti-hydrolysis crosslinkers extend filler longevity by preventing enzymatic breakdown.
| Type | Characteristics | Typical Uses |
|---|---|---|
| Sulfur-Based | Forms flexible sulfur bridges, common in rubber | Tires, seals, elastomers |
| Peroxides | Carbon-carbon bonds, high thermal stability, no discoloration | Thermoplastics, specialized rubbers |
| Silanes | Moisture-curing, used in adhesives and coatings | Sealants, paints, plastics |
| Anti-Hydrolysis Agents | Stable bonds against moisture, often carbodiimides or isocyanates | Plastics, coatings, medical applications |
Carbodiimide crosslinkers contain the reactive group N=C=N and offer several advantages:
Cure at room temperature, reducing energy consumption
Increase coating durability and scratch resistance
Lower moisture sensitivity
When combined in two-component (2K) systems, carbodiimide crosslinkers create dense network structures that further enhance the longevity of materials.
Modern crosslinking research aims to develop greener processes with lower VOC emissions and energy use. Biodegradable crosslinkers and more efficient curing methods are under active development to meet stricter environmental regulations.
Selecting an appropriate crosslinker depends on:
Material Type: Thermoplastics, thermosets, rubbers, or composites
Application Needs: Heat resistance, hydrolytic stability, mechanical strength
Processing Conditions: Curing temperature, reaction time, compatibility with additives
Using an anti-hydrolysis crosslinking agent is particularly crucial when long-term moisture resistance is required.
Q1: What is the difference between polymerization and crosslinking?
Polymerization links monomers to form long chains, while crosslinking connects these chains to form a three-dimensional network.
Q2: Are anti-hydrolysis crosslinkers safe for medical use?
Yes, agents like BDDE used in dermal fillers are well-studied and widely accepted for safety.
Q3: Does crosslinking affect recyclability?
Crosslinked materials are generally harder to recycle due to their network structure, but advances in chemical recycling are ongoing.
Crosslinking agents are essential for enhancing the physical and chemical properties of polymers across industries. The development and use of anti-hydrolysis crosslinking agents specifically address the challenge of moisture-induced degradation, enabling longer-lasting, more reliable materials in applications ranging from automotive to medical. As technologies evolve, these agents will continue to improve material performance while meeting environmental and regulatory demands.
