Pressure- and Temperature-Dependent Crystallization Kinetics of Isotactic Polypropylene under Process Relevant Conditions
| Autor: | René Androsch, Regine Boldt, Ines Kuehnert, Yvonne Spoerer |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Polypropylene
Crystallography Materials science crystallization kinetic General Chemical Engineering Comonomer Nucleation fast scanning chip calorimetry Molding (process) Condensed Matter Physics law.invention Inorganic Chemistry chemistry.chemical_compound chemistry Chemical engineering QD901-999 law Tacticity Copolymer General Materials Science Crystallization Material properties pvT-behavior polypropylene |
| Zdroj: | Crystals, Vol 11, Iss 1138, p 1138 (2021) Crystals Volume 11 Issue 9 |
| ISSN: | 2073-4352 |
| DOI: | 10.3390/cryst11091138 |
| Popis: | In this study, a non-nucleated homopolymer (HP) and random copolymer (RACO), as well as a nucleated HP and heterophasic copolymer (HECO) were investigated regarding their crystallization kinetics. Using pvT-measurements and fast scanning chip calorimetry (FSC), the crystallization behavior was analyzed as a function of pressure, cooling rate and temperature. It is shown that pressure and cooling rate have an opposite influence on the crystallization temperature of the materials. Furthermore, the addition of nucleating agents to the material has a significant effect on the maximum cooling rate at which the formation of α-crystals is still possible. The non-nucleated HP and RACO materials show significant differences that can be related to the sterically hindering effect of the comonomer units of RACO on crystallization, while the nucleated materials HP and HECO show similar crystallization kinetics despite their different structures. The pressure-dependent shift factor of the crystallization temperature is independent of the material. The results contribute to the description of the relationship between the crystallization kinetics of the material and the process parameters influencing the injection-molding induced morphology. This is required to realize process control in injection molding in order to produce pre-defined morphologies and to design material properties. |
| Databáze: | OpenAIRE |
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