文献类型：期刊文献

英文题名：Supercritical Carbon Dioxide Induced Foaming of Highly Oriented Isotactic Polypropylene

作者：Bao, Jin-Biao[1,2];Liu, Tao[1];Zhao, Ling[1];Barth, Danielle[2];Hu, Guo-Hua[2,3]

机构：[1]East China Univ Sci & Technol, State Key Lab Chem Engn, Shanghai 200237, Peoples R China;[2]Univ Lorraine, ENSIC, CNRS, Lab React & Proc Engn, F-54001 Nancy, France;[3]Maison Univ, Inst Univ France, F-75005 Paris, France

年份：2011

卷号：50

期号：23

起止页码：13387

外文期刊名：INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH

收录：;EI(收录号：20114914579243);WOS:【SCI-EXPANDED(收录号:WOS:000297445500056)】；

基金：The authors are grateful to the National Natural Science Foundation of China (Grants 20976045, 20976046), Shanghai Shuguang Project (08SG28), Program for New Century Excellent Talents in University (NCET-09-0348), 111 Project (B08021), and "the Fundamental Research Funds for the Central Universities" for support.

语种：英文

外文关键词：Polypropylenes - Cytology - Crystalline materials - Cells - Injection molding - Supercritical fluid extraction

摘要：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 degrees C). When the foaming temperature is 143 degrees C, a uniform open nanocellular morphology is obtained. The cell size and cell density both increase with foaming temperature from 135 to 143 degrees 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 degrees 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.