Crystallization of Polypropylene with a minute amount of beta-nucleator

Abstract

The work deals with crystallization of isotactic polypropylene (iPP) containing a low amount of beta-nucleating agent. Commercially available iPP was modified by 0.01 and 0.03 mass% of beta-specific nucleating agent and crystallized isothermally and non-isothermally under precisely controlled conditions in a differential scanning calorimeter. A strong effect of crystallization temperature (T (c)) and content of beta-nucleating agent on beta-phase formation was observed. In the sample with the high amount of nucleating agent, the beta-phase formation ceased with T (c) increase. In case of low-nucleated sample the opposite effect was observed. A non-isothermal crystallization showed that iPP with 0.01 mass% of the nucleating agent crystallized in the lowest temperature range, lower than that of non-nucleated iPP.