Is compatibility critical in polymer engineering?

The paper focuses on the necessity for compatibilization in polymer blends and composites due to the differing chemical nature of the components, which causes antagonism on the contacting surfaces. To achieve stable polymer blends and composites with the correct set of properties, this thermodynamically driven antagonism must be smoothed because it may result in dephasing. Typically, this is accomplished by including a third component, a compatibilizer. The review focuses on compatibilization strategies based on component peculiarities, that is, without the addition of a specially synthesized third component. They include the ability of components to participate in chemical interactions such as additional condensation and transreactions, hydrolytic reactions or hydrogen bonding, or the production of co-crystals and transcrystalline layers. Finally, single polymer composites are discussed as a case where compatibilization is not required.