scholarly journals Enhancement of Dimensional Stability of Compressed Open Cell Rigid Polyurethane Foams by Thermo-Mechanical Treatment

2015 ◽  
Vol 50 (1) ◽  
pp. 30-34
Author(s):  
WonSool Ahn
Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1392 ◽  
Author(s):  
Guangyu Zhang ◽  
Yumin Wu ◽  
Weisheng Chen ◽  
Dezhi Han ◽  
Xiaoqi Lin ◽  
...  

Bio-based polyurethane materials with abundant open-cells have wide applications because of their biodegradability for addressing the issue of environmental conservation. In this work, open-cell rigid polyurethane foams (RPUFs) were prepared with bio-based polyols (BBPs) derived from the liquefaction of peanut shells under different post-processing conditions. The influences of the neutralization procedure and filtering operation for BBPs on the foaming behaviors, density, dimensional stability, water absorption, swelling ratio, compressive strength, and microstructure of RPUFs were investigated intensively. The results revealed that a small amount of sulfuric acid in the polyols exhibited a great impact on physical and chemical properties of RPUFs while the filtering operation for those polyols had a slight effect on the above properties. The RPUFs prepared from neutralized BBPs possessed higher water absorption, preferable dimensional stability and compression strength than that fabricated from the non-neutralized BBPs. Moreover, the prepared RPUFs exhibited preferable water absorption of 636–777%, dimensional stability of <0.5%, compressive strength of >200 KPa, lower swelling rate of ca. 1%, as well as uniform cell structure with superior open-cell rate, implying potential applications in floral foam.


2017 ◽  
Vol 102 ◽  
pp. 88-96 ◽  
Author(s):  
N.E. Marcovich ◽  
M. Kurańska ◽  
A. Prociak ◽  
E. Malewska ◽  
K. Kulpa

1995 ◽  
Vol 31 (1) ◽  
pp. 24-37 ◽  
Author(s):  
K. Kodama ◽  
K. Yuge ◽  
Y. Masuda ◽  
Y. Tanimoto

1993 ◽  
Vol 29 (5) ◽  
pp. 429-430
Author(s):  
K. Kodama ◽  
K. Yuge ◽  
Y. Masuda ◽  
Y. Tanimoto

Author(s):  
L.E. Murr

Ledges in grain boundaries can be identified by their characteristic contrast features (straight, black-white lines) distinct from those of lattice dislocations, for example1,2 [see Fig. 1(a) and (b)]. Simple contrast rules as pointed out by Murr and Venkatesh2, can be established so that ledges may be recognized with come confidence, and the number of ledges per unit length of grain boundary (referred to as the ledge density, m) measured by direct observations in the transmission electron microscope. Such measurements can then give rise to quantitative data which can be used to provide evidence for the influence of ledges on the physical and mechanical properties of materials.It has been shown that ledge density can be systematically altered in some metals by thermo-mechanical treatment3,4.


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