Development of a multiple-hole die for the production of single large blocks of low-density polystyrene using carbon dioxide as a blowing agent

2011 ◽  
Vol 51 (11) ◽  
pp. 2328-2334 ◽  
Author(s):  
Jaap van Spronsen ◽  
Jeroen P.H. van Luijtelaer ◽  
Albert Stoop ◽  
J. Christian Scheper ◽  
Tjerk J. de Vries ◽  
...  
RSC Advances ◽  
2016 ◽  
Vol 6 (109) ◽  
pp. 108056-108066 ◽  
Author(s):  
Mehdi Saniei ◽  
Minh-Phuong Tran ◽  
Seong-Soo Bae ◽  
Piyapong Boahom ◽  
Pengjian Gong ◽  
...  

A homogeneous low-density nano-porous medium of isotactic polypropylene (iPP) with a low thermal conductivity was fabricated using supercritical carbon dioxide (scCO2).


2018 ◽  
Vol 29 (10) ◽  
pp. 2643-2654 ◽  
Author(s):  
Jia-li Peng ◽  
Xuan-long Peng ◽  
James Runt ◽  
Chao-ming Huang ◽  
Kuo-shien Huang ◽  
...  

2019 ◽  
Vol 56 (1) ◽  
pp. 73-88
Author(s):  
Raphael Vincent ◽  
Martin Langlotz ◽  
Matthias Düngen

Decreased viscosity due to the influence of blowing agent in thermoplastic polymer melts is a key issue for understanding the process of foam extrusion. In a process for direct foam extrusion, a novel approach for inline viscosity measurement of single-phase systems in single screw extruders is used to experimentally evaluate a viscosity decrease. Two blowing agents (propane and carbon dioxide) are tested for their effect on the viscosity of a polypropylene melt. While mass fractions of blowing agent below [Formula: see text] show little to no effect in regard to viscosity reduction compared to a pure polymer melt, a mass fraction of [Formula: see text] already results in significantly decreased viscosity values. While melt temperature influences the viscosity of the polymer melt, measurements show no significant additional effect in regard to a lowered viscosity of a single-phase system of polymer and fully dissolved blowing agent.


Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 89 ◽  
Author(s):  
Hai-Chen Zhang ◽  
Chun-Na Yu ◽  
Yong Liang ◽  
Gui-Xiang Lin ◽  
Cong Meng

The foaming process and cellular morphologies of poly(styrene-co-acrylonitrile) (SAN)/chlorinated polyethylene (CPE) blends with supercritical carbon dioxide (scCO2) as a blowing agent were investigated in this study. As compared to pure SAN foam in the same batch, the foamed blends with various CPE elastomer content had smaller average pore size and larger cell density. This is probably related to the inhibition of bubble growth by elastomer, resulting in poor melt flowability and strong viscoelasticity, and the efficient bubble heterogeneous nucleation caused by numerous phase interfaces inside the incompletely compatible blend system. In addition, many tiny interconnected holes through the pore walls were formed to connect adjacent micropores in foamed blend samples. The formation mechanism of such interconnected pores is probably due to the fracture of stretched melt around the bubble from phase interfaces with weak interactions. These facts suggest an effective path to control pore size, cell density and even interconnected pores of blend foams depends on the compatibility of the blend system and difference in foamability of individual components in supercritical CO2.


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