| Titre : | Supercritical carbon dioxide induced foaming of highly oriented isotactic polypropylene (2012) |
| Auteurs : | Jin-Biao Bao, Auteur ; Tao Liu, Auteur ; Ling Zhao, Auteur |
| Type de document : | Article : texte imprimé |
| Dans : | Industrial & engineering chemistry research (Vol. 50 N° 23, Décembre 2011) |
| Article en page(s) : | pp. 13387–13395 |
| Note générale : | Chimie industrielle |
| Langues : | Anglais |
| Tags : | Dioxide Carbon Isotactic Polypropylene |
| Résumé : | A highly oriented isotactic polypropylene (iPP) with a shish-kebab crystalline structure is used as a template to achieve nanocellular foams by CO2 foaming in the solid state. The shish-kebab crystalline structure is obtained by tuning injection-molding conditions. Nanocells are generated in amorphous domains confined by shish-kebab crystalline domains which cannot foam. The highly oriented iPP consists of both shish-kebab crystalline structure and spherulites structure and is used to investigate the effect of the crystalline morphology on the cell formation at a given CO2 saturation pressure (15 MPa) and various foaming temperatures (135, 140, 143, and 146 °C). When the foaming temperature is 143 °C, a uniform open nanocellular morphology is obtained. The cell size and cell density both increase with foaming temperature from 135 to 143 °C due to the fact that more crystals are molten, providing more space for cell nucleation and growth. However, when the foaming temperature is increased to 146 °C, the cell size abruptly increases from dozens of nanometers to dozens of micrometers, and the corresponding cell density decreases by several orders of magnitude. |
| DEWEY : | 660 |
| ISSN : | 0888-5885 |
| En ligne : | http://pubs.acs.org/doi/abs/10.1021/ie2018228 |
