NUCLEATING AGENTS & CLARIFIERS
Nucleating agents promote the crystallization of semi-crystalline polymers. These additives function by presenting a heterogeneous surface to the polymer melt, making the crystallization process more thermodynamically favorable. As a result of the this effect, the temperature at which the polymer begins to crystallize from the melt is increased, as are the rate of nucleation and overall rate of crystallization. Nucleating agents also promote the formation of smaller and more numerous spherulites, often giving enhanced properties such as flexural modulus and heat deflection temperature (HDT).
Nucleating agents are most widely used in polypropylene (homo- and random co-polymers), where they provide three main benefits: property enhancement, improved molding productivity, and increased transparency. Some special nucleating agents produce spherulites so small that they do not scatter visible light, providing transparent polypropylene. Products that provide this effect are referred to as clarifiers (or clarifying agents).
Nucleating agents are also useful in other semi-crystalline polymers, including polyesters (PET, PBT) and polyamides. Amfine's NA-05 nucleating agent is a unique product specially developed for use in polyesters.
Clarifiers for Polypropylene
Nucleating Agents for Polypropylene