Revolutionize Polyurethane Elastomers (TPU/CPU/MPU) with Carbodiimide Anti-hydrolysis Agent

Polyurethane elastomers—including TPU (Thermoplastic Polyurethane), CPU (Cast Polyurethane), and MPU (Microcellular Polyurethane)—are the workhorses of modern materials science. Valued for their unbeatable combination of elasticity, wear resistance, and moldability, they power everything from industrial mining screens to consumer smartphone cases, and even medical catheters. Yet, their full potential has long been held back by a critical flaw: hydrolysis. In complex environments—think high-temperature EV engine bays, humid tropical electronics, or acidic mining slurries—water molecules attack the ester, urethane, and urea groups in these elastomers, triggering rapid degradation. Reduced tensile strength, lost elasticity, and premature failure. This is where the Carbodiimide Anti-hydrolysis Agent changes the game. By neutralizing hydrolysis at the molecular level, it preserves the performance of TPU, CPU, and MPU, breaking through traditional application limits and opening new doors in industrial, consumer, and medical sectors.

Why TPU/CPU/MPU Suffer Hydrolysis: Mechanisms & Failure Modes

To understand how Carbodiimide Anti-hydrolysis Agent revolutionizes polyurethane elastomers, we first need to unpack why these materials are so vulnerable to hydrolysis. Their degradation isn’t random—it’s rooted in their chemical structure and amplified by harsh environmental conditions.

Structural Vulnerabilities: The "Weak Links" in Polymer Chains

All polyurethane elastomers share functional groups that act as hydrolysis hotspots:

• Ester groups: Dominant in polyester-type TPU and CPU, these groups are the most susceptible to water attack. When exposed to moisture, ester bonds (–COO–) split into carboxylic acids (–COOH) and alcohols. These carboxylic acids then act as catalysts, accelerating further bond cleavage in an autocatalytic cycle—a single acid molecule can break hundreds of additional polymer chains.

• Urethane/urea groups: Present in all polyurethane elastomers (even polyether-type TPU), these groups (–NHCOO– or –NHCONH–) also hydrolyze, though more slowly than esters. The result is still destructive: reduced molecular weight and weakened material integrity.

Elastomer-Specific Failure Patterns

Each type of polyurethane elastomer exhibits unique hydrolysis-induced failures, directly limiting its use:

• TPU: Thermoplastic and widely used in extrusion (e.g., cable jackets) and injection molding (e.g., phone cases). Hydrolysis causes it to soften initially, then become brittle—losing up to 60% of its tear resistance after 1,000 hours in 60℃ water (3–5x faster degradation than at room temperature) .

• CPU: Cast into thick, durable parts like mining screen panels and industrial bushings. Hydrolysis leads to surface cracking and internal voids; in acidic mine slurries (pH 4.0–5.0), untreated CPU can fail in as little as 3 months .

• MPU: Microcellular (foam-like) and used in consumer goods (e.g., shoe insoles) and medical devices (e.g., wound dressings). Hydrolysis increases its compression set (permanent deformation after pressure) and causes structural collapse—untreated MPU insoles lose 50% of their cushioning in 1 year of humid use .

Environmental Triggers That Accelerate Hydrolysis

Hydrolysis doesn’t happen in a vacuum; specific conditions amplify its effects, creating "complex environments" where unprotected elastomers fail:

• High temperature (>50℃): Speeds up water-polymer reactions—each 10℃ increase can double hydrolysis rates .

• High humidity (>85% RH): Increases moisture absorption into the polymer matrix, especially critical for consumer goods in tropical regions.

• Acidic/alkaline media: Common in industrial settings (e.g., mining, wastewater treatment) and medical applications (e.g., bodily fluids), these environments break down ester/urethane groups faster than neutral conditions.

• Metal ion contamination: Trace metals (e.g., iron from mining equipment) act as catalysts, further accelerating degradation.

Carbodiimide Anti-hydrolysis Agent: Mechanism & Core Advantages

The Carbodiimide Anti-hydrolysis Agent isn’t just a "band-aid" for hydrolysis—it’s a targeted solution that stops degradation at its source. Its superiority over traditional stabilizers (like epoxy or amine-based additives) makes it the ideal choice for polyurethane elastomers.

How Carbodiimide Anti-hydrolysis Agent Works: Molecular-Level Protection

The agent’s power lies in its unique chemical structure, defined by the reactive –N=C=N– group. Here’s its step-by-step mechanism:

1. Intercept Harmful Byproducts: When hydrolysis generates carboxylic acids (the main catalysts of degradation), the –N=C=N– group reacts with these acids.

2. Form Stable Bonds: The reaction produces inert urea linkages (–NHCONH–) instead of reactive carboxylic acids. This eliminates the autocatalytic cycle, halting further chain scission.

3. Repair Broken Chains: Polymeric carbodiimides (a key variant of the agent) go a step further: their long polymer chains reconnect partially broken polyurethane segments, restoring molecular weight and mechanical properties.

This mechanism is far more effective than alternatives. For example, epoxy-based stabilizers only "cap" carboxylic acids temporarily, while carbodiimides permanently neutralize them—providing long-term protection.

Core Advantages Over Traditional Anti-hydrolysis Additives

To highlight why Carbodiimide Anti-hydrolysis Agent is the best choice for TPU/CPU/MPU, we’ve compared it to common alternatives:

Our proprietary Bio-SAH™ series exemplifies these advantages: Bio-SAH™ 342Liquid (polymeric carbodiimide) and Bio-SAH™ 362Powder (monomeric carbodiimide) are tailored for polyurethane elastomers, ensuring no loss of elasticity while delivering industry-leading hydrolysis protection.

Application-Specific Efficacy: Protecting Performance in Complex Environments

The true value of Carbodiimide Anti-hydrolysis Agent shines in real-world applications. By preserving TPU/CPU/MPU performance in harsh, complex environments, it solves long-standing pain points for industrial and consumer manufacturers.

Industrial Sector: Withstanding Extreme Conditions

Industrial applications demand elastomers that can handle high temperatures, chemicals, and constant wear—areas where untreated polyurethane fails quickly.

• Mining & Construction (CPU):

  Challenge: CPU screen panels and liners are exposed to acidic water-based slurries (pH 4.0–5.5) and 60–80℃ temperatures. Untreated CPU fails in 3–4 months due to cracking and powdering.

  Solution: Adding 1.5–2.0 phr (parts per hundred resin) of Bio-SAH™ 342Liquid to CPU formulations.

  Result: CPU lifespan extends to 9–12 months (3x longer), with 90% of original tear strength retained after 1,000 hours of slurry immersion .

• Automotive & EV (TPU/CPU):

  Challenge: TPU seals (for battery enclosures) and CPU bushings (for suspension systems) face 120℃+ underhood temperatures and electrolyte vapors (from EV batteries). Untreated TPU loses 40% of its tensile strength in 6 months.

  Solution: TPU uses 0.8–1.2 phr Bio-SAH™ 362Powder; CPU uses 1.2–1.8 phr Bio-SAH™ 342Liquid.

  Result: TPU seals retain <5% compression set (vs. 25% for untreated) and maintain electrical insulation—critical for EV battery safety. CPU bushings last 2x longer in underhood environments .

• Marine Engineering (TPU):

  Challenge: TPU hoses and gaskets in boats are exposed to saltwater (3.5% NaCl) and cyclic moisture. Untreated TPU degrades in 1 year due to salt-induced hydrolysis.

  Solution: 1.0–1.5 phr Bio-SAH™ 342Liquid in TPU.

  Result: After 5,000 hours of salt spray testing, TPU retains 92% tensile strength (vs. 40% for untreated) and shows no surface cracking .

Consumer Sector: Ensuring Long-Term Durability

Consumer products rely on polyurethane elastomers for comfort and aesthetics—hydrolysis-induced brittleness or discoloration leads to customer complaints and returns.

• Footwear & Sports Gear (TPU/MPU):

  Challenge: TPU shoe soles and MPU insoles are exposed to sweat (pH 5.0–6.5), rain, and temperature cycles (10–40℃). Untreated MPU insoles lose 50% cushioning in 1 year.

  Solution: TPU soles use 0.5–0.8 phr Bio-SAH™ 362Powder; MPU insoles use 0.8–1.0 phr Bio-SAH™ 342Liquid.

  Result: MPU insoles retain <10% compression set after 2 years of use, avoiding brittleness. TPU soles show no yellowing or cracking—critical for brand aesthetics .

• Electronics (TPU):

  Challenge: TPU phone cases and charging cable jackets in tropical regions (95% RH, 35–40℃) suffer surface cracking and reduced flexibility. Untreated TPU cases fail in 8–10 months.

  Solution: 0.6–0.9 phr Bio-SAH™ 362Powder in TPU.

  Result: TPU cases retain 98% elongation at break after 18 months of humid use, with no cracking—extending product lifespan by 2x .

• Medical Devices (MPU/TPU):

  Challenge: MPU wound dressings and TPU catheter tubes are exposed to bodily fluids (pH 4.0–8.0) and sterilization cycles (autoclaving at 121℃). Untreated MPU loses structural integrity in 30 days.

  Solution: MPU uses 1.0–1.2 phr FDA-compliant Bio-SAH™ 372N; TPU uses 0.8–1.0 phr Bio-SAH™ 362Powder.

  Result: MPU dressings maintain 95% tensile strength after 30 days of immersion in bodily fluids. TPU catheters withstand 50+ autoclave cycles without degradation—meeting medical device standards .

Expanding Application Boundaries: From Traditional to Emerging Fields

Before Carbodiimide Anti-hydrolysis Agent, polyurethane elastomers were restricted to low-risk environments (e.g., indoor consumer goods). Today, the agent unlocks new, high-value applications by making TPU/CPU/MPU resilient enough for previously off-limits sectors—aligned with 2024’s top industry trends.

1. 5G Electronics: Enabling Humidity-Resistant Components

5G base stations and mmWave antennas require elastomeric gaskets and insulation that perform in outdoor, high-humidity environments (90% RH, 45℃). Previously, TPU was avoided due to hydrolysis-induced insulation loss. With Bio-SAH™ 342Liquid, TPU gaskets now retain electrical resistance above 10¹² Ω for 3 years—critical for 5G signal integrity. Major telecom manufacturers (e.g., Huawei, Ericsson) have adopted this solution for 2024 base station deployments .

2. Bio-Based Polyurethane Elastomers: Balancing Sustainability and Durability

The shift to bio-based materials (e.g., castor oil-derived TPU) is a key sustainability trend. However, bio-based TPU is more hydrolysis-susceptible than petroleum-based variants. Carbodiimide Anti-hydrolysis Agent solves this: adding 0.8–1.2 phr Bio-SAH™ 362Powder to bio-based TPU preserves 90% of its tensile strength after 1,000 hours of hydrolysis testing—while maintaining its biodegradability (per ASTM D638). This makes bio-based TPU viable for single-use consumer goods (e.g., biodegradable shoe soles) that need to resist moisture during use .

3. Long-Term Medical Implants: Meeting Strict Biocompatibility Standards

MPU and TPU are increasingly used in implantable devices (e.g., joint cushions, drug delivery tubes). However, hydrolysis in bodily fluids limited their lifespan to 2–3 years. With FDA-compliant Bio-SAH™ 372N, MPU implants now retain structural integrity for 5+ years—passing ISO 10993 biocompatibility tests (no cytotoxicity, no inflammation). This expands polyurethane elastomers into long-term orthopedic and cardiovascular applications .

4. Extreme-Temperature Industrial Automation

Industrial robots in semiconductor fabs operate in 150℃ cleanrooms with controlled humidity. Previously, CPU robot grippers failed in 6 months due to high-temperature hydrolysis. With 1.8–2.0 phr Bio-SAH™ 342Liquid, CPU grippers now last 18 months—reducing maintenance costs for chip manufacturers .

Practical Guide: Selecting & Applying Carbodiimide Anti-hydrolysis Agent

To maximize the benefits of Carbodiimide Anti-hydrolysis Agent for TPU/CPU/MPU, manufacturers need to tailor their selection and application to the elastomer type and end-use environment.

Step 1: Select the Right Carbodiimide Variant

Different polyurethane elastomers require different carbodiimide formulations—matching the agent to the elastomer’s processing method and structure is critical:

Step 2: Best Practices for Application

Even the right agent fails without proper integration. Follow these tips to ensure uniform protection:

• Add to the polyol component: For CPU and MPU, mix the carbodiimide into the polyol (not isocyanate) before curing—this ensures even dispersion throughout the elastomer matrix.

• Control processing temperatures: Avoid exceeding 270℃ for monomeric carbodiimides (e.g., Bio-SAH™ 362Powder) or 300℃ for polymeric variants—high temps cause agent decomposition.

• Pair with antioxidants: For high-temperature applications (e.g., EV underhood), combine Carbodiimide Anti-hydrolysis Agent with a primary antioxidant (e.g., Irganox 1010) to resist thermal-oxidative degradation—this creates a "dual shield" against heat and moisture.

Step 3: Validate Performance

After application, test the elastomer to confirm hydrolysis resistance:

• Accelerated aging: Use ASTM D570 (water absorption) and ISO 4611 to simulate 5+ years of use in 1,000 hours.

• Mechanical testing: Measure tensile strength, elongation at break, and compression set before and after aging—target retention of >85% for industrial applications and >90% for consumer/medical use.

Industry Trends & Future Innovation

The demand for Carbodiimide Anti-hydrolysis Agent in polyurethane elastomers is growing rapidly, driven by three key trends—and future innovations will further expand its impact.

1. EV & Battery Electrification: The #1 Demand Driver

Global EV production is expected to reach 35 million units by 2030, and each EV uses 5–10 kg of polyurethane elastomers (seals, bushings, battery insulation). As automakers push for 8+ year battery lifespans, the need for hydrolysis-resistant TPU/CPU is critical. Our Bio-SAH™ series is already specified by Tesla and BYD for 2025 EV models—expect this trend to drive 40% annual growth in carbodiimide demand for elastomers .

2. Sustainability: Bio-Based Carbodiimides

To align with bio-based polyurethane elastomers, manufacturers are developing plant-derived carbodiimides. Our R&D team is testing a castor oil-based carbodiimide that matches the performance of petroleum-based variants but reduces carbon footprint by 30%. This will launch in 2025, catering to brands aiming for fully sustainable elastomer formulations .

3. Multifunctional Formulations

Future Carbodiimide Anti-hydrolysis Agent will combine hydrolysis protection with other benefits:

• Anti-UV + Anti-hydrolysis: For outdoor consumer goods (e.g., patio furniture MPU cushions), eliminating the need for separate UV stabilizers.

• Low-Addition, High-Efficacy: New polymeric carbodiimides that deliver full protection at 0.3–0.5 phr (down from 0.5–1.2 phr today)—reducing costs and minimizing polymer modification.

Conclusion: Carbodiimide Anti-hydrolysis Agent—The Catalyst for Polyurethane Elastomer Innovation

For decades, hydrolysis has limited polyurethane elastomers to low-risk applications, leaving their full potential untapped. The Carbodiimide Anti-hydrolysis Agent changes that. By neutralizing carboxylic acids, halting autocatalytic degradation, and preserving mechanical properties, it transforms TPU, CPU, and MPU into materials that thrive in complex environments—from EV engine bays to tropical electronics, and even medical implants.Its impact goes beyond durability: it expands application boundaries, enabling manufacturers to enter high-growth sectors like 5G and bio-based elastomers. It reduces waste by extending product lifespans, aligning with sustainability goals. And it delivers measurable ROI—lower maintenance costs for industrial users, fewer returns for consumer brands, and compliance with strict medical standards.For anyone working with polyurethane elastomers, the message is clear: to revolutionize your TPU, CPU, or MPU products, start with the Carbodiimide Anti-hydrolysis Agent.

Ready to unlock the full potential of your TPU, CPU, or MPU formulations? Explore our Bio-SAH™ product lineup—tailored for extrusion, casting, and foaming processes. Download our technical datasheet for EV-specific test data, or contact our team to run custom aging tests for your application. Let’s build hydrolysis-resistant polyurethane elastomers that power the products of tomorrow.

FAQ

Q: How does Carbodiimide Anti-hydrolysis Agent help TPU/CPU/MPU?

A: Stops hydrolysis, preserves elasticity/tensile strength, extends lifespan in harsh environments.

Q: How to choose the right agent for TPU/CPU/MPU?

A: Match use—362Powder for TPU extrusion and MPU, 342Liquid for CPU casting.

Q: Does it affect elastomers’ elasticity?

A: No, it maintains flexibility without negative impact.

Q: What’s the optimal addition level?

A: 0.5–2.0 phr, varying by elastomer type.