Rubber crystallization, nucleating agent

Microstructure-property correlations in dynamically vulcanized thermoplastic elastomers based on polypropylene (PP)/EPDM have shown that clay was nearly exfoliated and randomly distributed into the continuous polypropylene phase [23]. SEM photomicrographs revealed that the size of rubber particles increased with clay incorporation. Also, the clay layers act as nucleating agents, resulting in higher crystallization temperature and reduced degree of crystallinity. 

Substituted phenols that act as scavengers for radicals formed in the course of the degradation reaction as well as thio compounds and organophosphites are added as antioxidants. Benzophenone and carbon black act as UV stabilizers. Calcium stearate or other carboxylic acids are added to bind chloride originating from the catalyst. Further additives can be acceptors for coloring, anti-electrostatics, nucleating agents to promote crystallization, lubricants, or flame retardants [507,508]. Polypropene can also be blended with other polymers as rubbers (EPDM) or polyethene [509-511]. In these products the... 

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