Investigation of the crystalline phase morphology of a β-nucleated impact polypropylene copolymer
Journal of Applied Polymer Science
Department of Chemistry, University of the Free State (Qwaqwa Campus), Phuthaditjhaba, South Africa; Department of Chemistry and Polymer Science, University of Stellenbosch, Stellenbosch, South Africa
This study covers the preparation and the characterization of β-nucleated impact polypropylene copolymer (NA-IPC). Calcium stearate (CaSt), as well as pimelic (Pim) and adipic (Adi) acids, were doped into IPC as mono- or bicomponent nucleating agents (NAs) at varying mass ratios. Possible chemical interactions between the NAs and with IPC, as well as the effect of the NAs on the crystallization behavior and nonisothermal crystallization kinetics, were investigated. DSC and XRD results revealed that IPC nucleated with Pim and Pim-CaSt nucleants induced up to 90% β-crystals, whereas Adi and Adi-CaSt formed only about 17% β-crystals. This was associated with the strong nucleation efficiency of Pim. The nonisothermal crystallization kinetics showed that the crystallization of IPC and NA-IPC followed a three-dimensional growth with athermal nucleation mechanism. FTIR showed that none of the NAs chemically reacted with IPC, and the chemical structure of the polymer was thus intact during the treatment. © 2013 Wiley Periodicals, Inc.
Chemical interactions; Crystallization behavior; Impact polypropylene copolymer; Nonisothermal crystallization kinetics; Nucleation efficiency; Nucleation mechanism; Structure of the polymers; Three-dimensional growth; Copolymers; Crystallization; Differential scanning calorimetry; Enzyme kinetics; Isotherms; Kinetics; Nucleation; X rays; Polypropylenes