Flexibility or Toughness ? – The Design of Thermoset Toughening Agents

Abstract

Functional toughening agents, incorporated as separate microphases into rigid highly crosslinked polymeric matrices, are the key component of high-performance structural materials which exhibit high impact and fatigue resistance without sacrificing high stiffness, dimensional stability, strength, and heat distortion temperature. The chemistry and the basic structure/property relationships of various polymeric flexibilizers and toughening agents applied in the aerospace, aircraft, and automotive industries are reviewed. Special emphasis is given to the role of polymer compatibility in the design of functional liquid rubbers, reactive thermoplastic oligomers, and functional core/shell microparticles. Some of the major synthetic routes to advanced structural materials based on thermoset resin chemistry and functional supermolecular structures are outlined.