12. Blends and Alloys

Thus far, the focus has been on different classes of thermoplastics and their properties, which differ considerably among each other. While new polymeric materials are being synthesized, scaling up and marketing of new polymers can be so expensive that, even when superior properties have been demonstrated, they may not be commercialized. An alternative strategy for developing new materials with desired characteristics – such as better mechanical properties, including impact performance; higher thermal performance; improved processability, especially for high-temperature materials; and improved surface appearance – at lower costs is to mix different polymers. Such mixtures are called polymer blends.