Influence of molecular structure on the rheological properties and foamability of long chain branched polypropylene by 'one-pot' reactive extrusion
| Autor: | Zhen Yao, Shao-long Qiu, Yan Li, Changchun Zeng, Kun Cao |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Polypropylene
Materials science Polymers and Plastics Dicumyl peroxide 02 engineering and technology General Chemistry Reactive extrusion 021001 nanoscience & nanotechnology chemistry.chemical_compound 020401 chemical engineering chemistry Chemical engineering Rheology Materials Chemistry Molecule Extrusion 0204 chemical engineering 0210 nano-technology Long chain |
| Zdroj: | Journal of Cellular Plastics. :0021955X2094310 |
| ISSN: | 1530-7999 0021-955X |
| DOI: | 10.1177/0021955x20943108 |
| Popis: | In this work, reactive twin screw extrusion was conducted to synthesize long chain branched polypropylenes (LCB-PPs) in a “one-pot” process in which dicumyl peroxide (DCP) initiated maleic anhydride (MAH) grafting onto the linear PP, and the concomitant coupling reaction between ethylene diamine (EDA) and MAH grafted polypropylene (PP-g-MAH) proceeded in series. Fourier transfer infrared spectroscopy (FTIR) on the prepared materials confirmed the occurrence of both reactions. A series of LCB-PPs were prepared using different amounts of EDA, MAH and DCP to study their effects and determine the optimal synthesis conditions. The prepared materials were characterized by size exclusion chromatography (SEC) and rheological analysis to ascertain the polymer microstructure. The foamability of the LCB-PPs by supercritical carbon dioxide (scCO2) foaming and foam morphology were investigated. The LCB-PPs were found to have vastly improved foamability and cellular morphology. Under optimal conditions, a foam expansion ratio of over 20 was achieved. |
| Databáze: | OpenAIRE |
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