The β-Nucleation in Polypropylene and Its Effect on the Mechano-Physical and Thermal Properties

摘要

Applying a nucleation agent was investigated for generation of the p-form in polypropylene which is a polymorph material. The β-propylene was produced from melt mixing of polypropylene and nucleating agent (combination of calcium stearate and pimelic acid) in a twin screw extruder. Studies on the β-form generation, including effects of different factors such as concentration of the nucleating agent, cooling rate, evaluation of melting and crystallization behaviors for the nucleated samples, were conducted by XRD and DSC analyses. Examination of the mechano-physical properties as well as thermal properties indicates that generation of β-form in polypropylene raised the crystallization temperature about 15°C, toughness and impact strength for 15%, thermal deformation temperature about 20°C, and also tensile strength and elongation at break show some extent. A reduction in flexural modulus and yield strength was also achieved in the β-form.