SABIC Introduces New Reactive Oligomer for Aerospace Thermoset Composites

SABIC launched a polyetherimide reactive oligomer designed to enhance the toughness and processing efficiency of primary and secondary aerospace composite structures.

The ULTEM SU3102P reactive oligomer is a polyetherimide (PEI) agent developed for use in wing structures, fuselage frames, spoilers, and interior components. This material achieves thermoplastic loadings of up to 50 percent by weight. Comparative data indicates that reactive polyethersulfone (rPES) typically permits loadings between 7 and 12 percent.

The oligomer improves the toughness-stiffness balance by up to 140 percent compared to rPES. This enhancement is intended to increase the resistance of composite materials to fractures and impact damage, potentially reducing maintenance requirements and improving structural durability.

Manufacturing and Process Compatibility
The ULTEM SU3102P oligomer maintains low formulation viscosity despite high loading levels. This characteristic supports consistent processing and can increase the productivity and energy efficiency of thermoset composite prepregs by up to 30 percent.

The material is compatible with various thermoset resin systems and can be integrated into existing manufacturing processes without significant modification. Technical properties inherited from the ULTEM portfolio include inherent flame retardance, high heat resistance, chemical resistance, and a low coefficient of thermal expansion (CTE).

Sergi Monros, vice president of SABIC Polymers, Specialties BU, stated that the oligomer allows for the creation of lighter, thinner, and tougher composite structures while supporting manufacturing efficiency. The material received a Gold award at the 2026 Edison Awards and is currently available in commercial quantities.

Additional Context
Thermoset composites are critical in aerospace engineering due to their high strength-to-weight ratios, but they are often inherently brittle. To address this, toughening agents are integrated into the resin matrix to prevent crack propagation. Traditional tougheners like rPES often face a trade-off where increasing the concentration to improve toughness significantly raises the viscosity of the resin, making it difficult to infuse into carbon or glass fiber reinforcements.

Oligomers are molecular complexes that serve as intermediate building blocks in polymer chemistry. In composite manufacturing, reactive oligomers chemically bond with the host resin during the curing process. This chemical integration allows for a more homogenous distribution of the toughening phase. High-loading capabilities in such materials are significant because they allow engineers to fine-tune the mechanical properties of a part—such as its ability to absorb energy during an impact—without compromising the thermal stability or chemical resistance required for flight-critical hardware.

Edited by Romila DSilva, Induportals Editor, with AI assistance.