Effect of metallic salts of pimelic acid and crystallization temperatures on the formation of β crystalline form in isotactic poly(propylene)

The effect of crystallization temperatures (100-140 degrees C) on the formation of beta crystalline,form in isotactic polypropylene nucleated by pimelic acid and sodium, magnesium, zinc, calcium, barium and aluminium salts of pimelic acid has been investigated. It is found that beta crystalline form can be produced from polypropylene melt, isothermally crystallized at 120 or 130 degrees C Aluminium pimelate is a a nucleator which suppresses the production of beta crystalline form in polypropylene. Pimelic acid and magnesium pimelate are weak beta nucleators. Sodium pimelate is a moderate beta nucleator. Zinc pimelate, calcium pimelate and barium pimelate are good beta nucleators for polypropylene with calcium pimelate being the best.