Estherm™ - Advanced Aromatic Polyesters

Estherm™ uses a new class of polyesters called aromatic thermosetting copolyesters (ATSP). ATSP is a high performance polymer that has the best of both thermoset and thermoplastic systems. It has high dimensional stability and performance like thermosets while being recyclable like thermoplastics.

Whether your application needs durable materials (high modulus, strength, hardness) or high temperature stability or low-flammability, Estherm™ can provide the right solution for you.  One of the unique capabilities of ATSP is its Self-Bond™ feature that is possible due to interchain transesterification reactions. We can optimize the polymer for your specific application needs.

Key Characteristics

  • High modulus (>3 GPa)
  • High working temperature (Tg > 250℃)
  • Solid-state reaction enabled at high temperatures, helps in processing of complex parts through additive manufacturing
  • Excellent oxidative stability
  • Very low moisture pickup
  • Non-flammable
  • Cryogenic-safe
  • Easy machinability — low dust

Estherm™ is available as both starting pre-polymer and cured bulk sheets and composites laminates. ATSP Innovations will work with you to help integrate Estherm™ into your manufacturing processes.

Estherm™ resin

Estherm™ resin

Resin powder than can be molded into any geometry using compression molding or spray-coated on various substrates. Available in various grades.

Estherm™ bulk sheets

Estherm™ bulk sheets

Machinable bulk sheet available in standard thickness. Perfect for light weight, high performance parts.
Estherm™ composite laminates

Estherm™ composite laminates

Continuous fiber reinforced with Estherm resin. Perfect for high strength, high Tg applications. Carbon and glass reinforcement available. Machinable and bendable.

Data Properties

Physical Properties EsthermTM
Density (g/cm3) 1.32
Color (Unfilled) Red/transparent
Thermal Properties EsthermTM
Short-term Thermal Stability (°C) 425 (Inert) 350 (In Air)
Coefficient of Thermal Expansion (1/K) 40 x 10-6
Mechanical Properties ASTM Standard EsthermTM
Compressive Modulus (GPa) D695 4.07
Compressive Strength (MPa) D695 303.8
Tensile Strength (MPa) D695 95
Young’s Modulus (GPa) D695 4.2
Dielectric constant (4.8 µm) (25°, 10 khZ)   5.0
Dielectric breakdown strength (4.1 µm) (V/µm)   384.4
Limiting Oxygen Index   40%


For high performance applications, there are no polymeric that have high glass transition temperatures while also having excellent dimensional stability, ease of processibility due to solid state reactions as well as excellent mechanical properties. ATSP was created at the Department of Materials Science and Engineering at the University of Illinois, Urbana Champaign in Prof. Jim Economy’s group. Over two decades of academic research has led to fully understanding the structure-property relationships of this new class of materials. The polymer can be easily tailored to give the right blend of properties. If you have a high temperature application in mind, we can tailor the right Estherm grade for you.


We are looking for partners, collaborators and customers to bring this unique technology to the industrial markets. Interested in joining us in this new frontier of structural adhesives? Contact us or request a quote.