PARALOID™ Impact Modifiers for Tougher Epoxy and MMA Thermoset Resins

What Are PARALOID™ Impact Modifiers?

PARALOID™ Impact Modifiers are highly dispersible core-shell rubber toughening agents designed for thermosetting resin systems. They introduce a finely dispersed secondary phase into the cured resin matrix that absorbs and dissipates energy during mechanical stress. This mechanism helps reduce crack initiation and propagation, resulting in tougher, more resilient thermoset materials.

The technology is available in both methacrylate-butadiene-styrene (MBS) and acrylic core-shell rubber chemistries, allowing formulators to select the best balance of processing, impact performance, thermal stability, and weatherability for their application.

Key advantages of PARALOID™ Impact Modifiers include:

• Improved toughness in brittle epoxy and MMA systems
• Easy dispersion into thermoset formulations
• Long shelf stability due to chemical stability
• High formulation flexibility through controlled particle size and rubber content
• Retention of important resin properties such as Tg, modulus, and reactivity

How Core-Shell Rubber Technology Works

PARALOID™ Impact Modifiers utilize a sophisticated multi-layer particle design engineered for effective toughening.

As shown in the first graphic above, each particle contains:

• A rubber core composed of butadiene, butadiene-styrene copolymer, or acrylic rubber that provides stress-induced toughening
• A methacrylate shell grafted onto the rubber core that promotes compatibility with epoxy and MMA resin systems

When stress is applied to a cured thermoset, the dispersed rubber particles absorb energy that would otherwise contribute to crack growth. Because the shell is engineered to be compatible with the resin matrix, the particles remain well dispersed and can efficiently transfer stress throughout the system.

Compared with conventional liquid toughening technologies, core-shell rubber modifiers can provide:

• Higher fracture toughness
• Improved adhesion to metal substrates
• Better formulation control through predefined particle size
• Lower impact on viscosity and thermal performance
• Consistent batch-to-batch reproducibility

Applications and Performance Benefits

Electronics and Copper-Clad Laminates

Electronic laminates and other epoxy-based electronic materials require a combination of mechanical durability, thermal performance, and processing reliability. Toughening solutions that reduce Tg can create downstream performance tradeoffs. PARALOID™ Impact Modifiers are designed to increase toughness while preserving final Tg, making them attractive for copper-clad laminates, epoxy molding compounds, and other electronic packaging applications.

Structural Adhesives

Structural adhesives often experience dynamic loads, vibration, thermal cycling, and impact stress. Brittle failure can limit long-term reliability, particularly when bonding metals and dissimilar substrates.

By incorporating core-shell rubber technology, formulators can improve elongation, fatigue resistance, and durability while supporting stronger adhesive performance. Enhanced lap shear performance on metal substrates further supports demanding transportation, industrial, and infrastructure applications.

The concepts described in ChemPoint's structural adhesive guidance are equally relevant across broader epoxy and MMA thermoset applications where toughness and durability are essential performance drivers.

Composites

Epoxy composites are widely used in aerospace, transportation, sporting goods, marine structures, wind energy components, and industrial equipment due to their strength-to-weight ratio and environmental resistance.

However, impact events and crack propagation remain key design concerns. PARALOID™ Impact Modifiers enhance fracture resistance and impact strength by dispersing CSR particles throughout the matrix. This approach can help improve composite durability while preserving many of the desirable mechanical and thermal characteristics of the base resin system.

Epoxy and MMA Concentrates

Predispersed concentrates and masterbatch systems are often used to simplify production and improve consistency.

PARALOID™ Impact Modifiers are well suited for concentrate development because their engineered particle structure enables efficient dispersion and reproducible performance. This can reduce mixing and dispersion requirements while streamlining manufacturing operations.

PARALOID™ Product Selection Guide

ChemPoint offers a focused portfolio of PARALOID™ Impact Modifiers for thermosetting resin applications.

Summary

PARALOID™ Impact Modifiers help overcome one of the primary limitations of thermosetting resins: brittleness. Through advanced core-shell rubber technology, these additives increase toughness, durability, and adhesive performance while maintaining the thermal and mechanical advantages that make epoxy and MMA systems so valuable. From electronics and structural adhesives to composites and concentrates, ChemPoint's PARALOID™ portfolio offers formulators multiple pathways to enhance performance and broaden application possibilities.

Ready to improve the toughness and durability of your epoxy or MMA formulation?

Click below to discuss grade selection, request a technical consultation, or request a sample of PARALOID™ Impact Modifiers.