Impacts of moisture absorption on electrical properties of rigid polyurethane foam for composite post insulator of UHVDC transmission line

2021 ◽  
Vol 131 ◽  
pp. 107098
Author(s):  
Yong Yi ◽  
Yingyue Sun ◽  
Liming Wang ◽  
Peng Xiao
Keyword(s):  
Electrical Properties ◽  
Transmission Line ◽  
Polyurethane Foam ◽  
Moisture Absorption ◽  
Rigid Polyurethane Foam ◽  
Post Insulator

Effect Of Moisture On The Physical Properties Of Polyimide Films

1991 ◽  
Vol 227 ◽  
Author(s):  
Rajeevi Subramanian ◽  
Michael T. Pottiger ◽  
Jacqueline H. Morris ◽  
Joseph P. Curilla
Keyword(s):  
Dielectric Constant ◽  
Steady State ◽  
Electrical Properties ◽  
Relative Humidity ◽  
Quartz Crystal ◽  
Moisture Absorption ◽  
Relative Dielectric Constant ◽  
Moisture Uptake ◽  
Polyimide Films ◽  
Effect Of Moisture

ABSTRACTMoisture absorption and its effect on electrical properties were measured for several polyimides. A Quartz Crystal Microbalance (QCM) was used to investigate the moisture absorption in BPDA/PPD, PMDA/ODA, and BTDA//ODA/MPD polyimides. The steady-state moisture uptake in polyimides as a function of relative humidity (RH) was determined by exposing film samples to successively higher RH values ranging from 10 to 85% at 25°C. The isothermal moisture absorption as a function of percent RH was found to be nearly linear for all of the polyimides studied. The effect of moisture on the electrical properties of a BPDA/PPD polyimide was also investigated. The relative dielectric constant at 25 °C was found to be a linear function of the moisture absorbed.

Experimental study of horizontal flame spread over rigid polyurethane foam on a plateau: effects of sample width and ambient pressure

2014 ◽  
Vol 39 (2) ◽  
pp. 127-138 ◽  
Author(s):  
Y. Zhou ◽  
H. H. Xiao ◽  
J. H. Sun ◽  
X. N. Zhang ◽  
W. G. Yan ◽  
...  
Keyword(s):  
Experimental Study ◽  
Polyurethane Foam ◽  
Flame Spread ◽  
Ambient Pressure ◽  
Rigid Polyurethane Foam ◽  
Sample Width
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