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Tailoring Mechanical Properties of Isotactic Polypropylene Via Crystallization of the Mesophase and Control of Stereodefects Concentration
Author(s) -
De Rosa Claudio,
Auriemma Finizia,
de Ballesteros Odda Ruiz,
Di Girolamo Rocco,
Tarallo Oreste,
Galotto Nella Galotto
Publication year - 2013
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.201300296
Subject(s) - tacticity , mesophase , crystallization , materials science , ultimate tensile strength , polypropylene , polymerization , polymer chemistry , composite material , modulus , elastic modulus , quenching (fluorescence) , chemical engineering , polymer , liquid crystal , physics , optoelectronics , quantum mechanics , fluorescence , engineering
A strategy to tailor the properties of isotactic polypropylene, based on the combination of the crystallization of the mesophase and the control of the molecular structure and concentration of stereodefects via polymerization with metallocene catalysts, is presented. The mechanical properties can be modulated through the conventional slow crystallization from the melt in the α and γ forms, depending on the concentration of stereodefects, or the crystallization of the mesophase by melt quenching. The most stereoirregular sample with rr concentration of 11% shows elastic behavior either when it is slowly crystallized in the γ form or when it is crystallized in the mesomorphic form, but with remarkable differences in the values of the modulus and tensile strength.