Premium
The supermolecular structure of isotactic polypropylene/atactic polystyrene blends
Author(s) -
Borysiak Slawomir
Publication year - 2011
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.22039
Subject(s) - materials science , tacticity , polystyrene , polypropylene , crystallization , nucleation , spherulite (polymer physics) , differential scanning calorimetry , polymer chemistry , maleic anhydride , compatibilization , polymer blend , phase (matter) , styrene , composite material , copolymer , polymer , chemical engineering , polymerization , thermodynamics , organic chemistry , chemistry , physics , engineering
The supermolecular structure of binary isotactic polypropylene/atactic polystyrene (iPP/PS) injection‐molded blends were studied by wide‐angle X‐ray diffraction, differential scanning calorimetry, and optical microscopy. The combination of different methods gives a possibility of analysis of relation between the phase transformation in polypropylene and crystallization parameters. Effect of compatibilization of poly(styrene‐b‐ethylene‐ co ‐butylene‐b‐styrene) grafted with maleic anhydride (SEBS‐g‐MA) block copolymers in the iPP/PS blends on the structure, nucleation, crystal growth, solidification, and the phase morphology was analyzed. We found that the β‐crystallization tendency of polypropylene matrix can be enhanced by adding atactic polystyrene. However, the incorporation of SEBS‐g‐MA into iPP/PS blends resulted in an important decrease in β‐content of iPP. It is evident that the presence of compatibilizing agent caused a very significant reduction of the α‐spherulite growth rates and the crystal conversion as well as increases of half‐time crystallization in comparison with the iPP/PS systems. The relation between kinetic parameters of crystallization process and polymorphic structure of iPP in blend systems has been satisfactorily explained. Moreover, a strong effect of processing parameters on the β‐phase formation was observed. The results clearly show that at a higher temperature of mold and lower injection speed, the amount of β‐phase of iPP matrix slightly decreases. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers