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Effects of CO 2 on crystallization kinetics of polypropylene

2001; Wiley; Volume: 41; Issue: 11 Linguagem: Inglês

10.1002/pen.10890

1548-2634

Mitsuko Takada, Masataka Tanigaki, Masahiro Ohshima,

biodegradable polymer synthesis and properties

Abstract When CO 2 dissolves into a polypropylene (PP), its crystallization kinetics changes These changes were studied, in the expectation that the information would reflect on the behavior of other semicrystalline polyolefins. The isothermal crystallizatior rate of the PP‐CO 2 solutions was measured using a high‐pressure differential scanning calorimeter (DSC), which performed calorlmetric measurements while keeping the polymer in contact with pressurized CO 2 . Although the measured crystallizatior rate followed the Avrami equation, the value of the crystallization kinetic constant was different from that measured for PP crystallized in air under atmospheric pressure. The dissolved CO 2 decreased the overall crystallization rate of PP within the nucleation dominated temperature region. This suggests that the dissolved CO 2 decreases the melting and the glass transition temperatures and prevents formation of critical size nuclei.