Foam processing and cellular structure of polypropylene/clay nanocomposites

Autor:	Pralay Maiti, Hirotaka Okamoto, Arimitsu Usuki, Naoki Hasegawa, Tadao Kotaka, Mitsuko Takada, Masami Okamoto, Pham Hoai Nam, Takashi Nakayama, Masahiro Ohshima
Rok vydání:	2002
Předmět:	Polypropylene Materials science Nanocomposite Polymers and Plastics Scanning electron microscope General Chemistry Atmospheric temperature range Supercritical fluid Matrix (geology) chemistry.chemical_compound Montmorillonite chemistry Rheology Materials Chemistry Composite material
Zdroj:	Polymer Engineering & Science. 42:1907-1918
ISSN:	1548-2634 0032-3888
DOI:	10.1002/pen.11083
Popis:	Polypropylene (PP)/clay nanocomposites (PPCNs) were autoclave-foamed in a batch process. Foaming was performed using supercritical CO 2 at 10 MPa, within the temperature range from 130.6°C to 143.4°C, i.e., below the melting temperature of either PPCNs or maleic anhydride-modified PP (PP-MA) matrix without clay. The foamed PP-MA and PPCN2 (prepared at 130.6°C and containing 2 wt% clay) show closed cell structures with pentagonal and/or hexagonal faces, while foams of PPCN4 and PPCN7.5 (prepared at 143.4°C, 4 and 7.5 wt% clay) had spherical cells. Scanning electron microscopy confirmed that foamed PPCNs had high cell density of 10 7 -10 8 cells/mL, cell sizes in the range of 30-120 μm, cell wall thicknesses of 5-15 μm, and low densities of 0.05-0.3 g/mL. Interestingly, transmission electron microscopic observations of the PPCNs' cell structure showed biaxial flow-induced alignment of clay particles along the cell boundary. In this paper, the correlation between foam structure and rheological properties of the PPCNs is also discussed.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::e7c8220bb2bdef59026afbb1a87259d3 https://doi.org/10.1002/pen.11083 Zobrazit plný text záznamu Plný text