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Solid Phase Modification of Poly(propylene). The Role of the Polymer Texture in the Peroxide Distribution
Author(s) -
LászlóHedvig Zsuzsa,
Dobai Enikö,
Korecz László,
Nagy Péter,
Hesse Achim,
Rätzsch Manfred,
Tüdös Ferenc
Publication year - 2001
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 - 10.1002/1521-3935(20010901)202:13<2696::aid-macp2696>3.0.co;2-j
Subject(s) - crystallite , peroxide , polymer , phase (matter) , texture (cosmology) , chemistry , polymer chemistry , radical , amorphous solid , solubility , organic peroxide , materials science , analytical chemistry (journal) , crystallography , organic chemistry , artificial intelligence , computer science , copolymer , image (mathematics)
Different poly(propylene)s were reacted with tert ‐butyl peroxybenzoate (TBPB) in solid phase and the time dependence of the concentration of tertiary polymer radicals ([A∗]) formed was measured by ESR spectroscopy at 145°C. The distribution (or solubility) of peroxide was found uneven (or limited), the segregation of solid dilauroyl peroxide (DLPO) was proved by DSC. It was found that not the crystalline/amorphous ratio was the decisive factor in poly(propylene)/peroxide solid phase reactions, but much more the crystallite size of the polymer texture. The latter was determined by X‐ray measurements. Poly(propylene)s with average crystallite diameters of about 250 Å showed a characteristic dependence on peroxide concentration in the solid phase reaction of tertiary carbon radical forming. The log [A∗] vs. time curves show a good linearity, the relationships correspond to a unimolecular overall kinetics. When the crystallite diameters were 17–40% less than 250 Å, the polymer radical concentration ([A∗]) did not show a characteristic dependence on TBPB concentration. Our findings are interpretable in terms of capillary condensation of peroxides.