Anisotropic Linear and Volumetric Thermal-Expansion Behaviors of Self-Standing Polyimide Films Analyzed by Thermomechanical Analysis (TMA) and Optical Interferometry

2017 ◽  
Vol 219 (3) ◽  
pp. 1700354 ◽  
Author(s):  
Shinji Ando ◽  
Kenji Sekiguchi ◽  
Masashi Mizoroki ◽  
Tomohiro Okada ◽  
Ryohei Ishige
Keyword(s):  
Thermal Expansion ◽  
Thermomechanical Analysis ◽  
Optical Interferometry ◽  
Polyimide Films ◽  
Volumetric Thermal Expansion

Synthesis and properties of low coefficient of thermal expansion copolyimides derived from biphenyltetracarboxylic dianhydride with p-phenylenediamine and 4,4′-oxydialinine

e-Polymers ◽  
2016 ◽  
Vol 16 (4) ◽  
pp. 295-302 ◽  
Author(s):  
Yonglin Lei ◽  
Yuanjie Shu ◽  
Jinhua Peng ◽  
Yongjian Tang ◽  
Jichuan Huo
Keyword(s):  
Thermal Stability ◽  
Thermal Expansion ◽  
Coefficient Of Thermal Expansion ◽  
Thermomechanical Analysis ◽  
Amic Acid ◽  
Molar Ratio ◽  
Structure And Property ◽  
Property Relations ◽  
Ft Ir ◽  
Biphenyltetracarboxylic Dianhydride

AbstractA series of copolyimides were prepared by thermal imidization of poly(amic acid)s (PAAs) derived from 3,3′,4,4′-biphenyltetracarboxylic dianhydride (s-BPDA), 2,3′,3,4′-biphenyltetracarboxylic dianhydride (a-BPDA), p-phenylenediamine (PDA) and 4,4′-oxydialinine (4,4′-ODA) commonly used for the production of commercial polyimides. The flexible copolyimide films were obtained from that the molar ratio of s-BPDA, a-BPDA, PDA and 4,4′-ODA was 9:1:8:2 (Co-PIs-3), 8:2:9:1 (Co-PIs-5) and 8:2:8:2 (Co-PIs-6). These obtained copolyimide films were characterized by Fourier transform-infrared spectroscopy(FT-IR), wide angle X-ray (WAXD), Thermogravimetric (TG), dynamic mechanical thermal analysis (DMA), thermomechanical analysis (TMA), field-emission scanning electron microscopy (FE-SEM) and mechanical properties measurement. The results showed that three copolyimides remained semi-crystalline and exhibited high glass transition temperature (Tg), high thermal stability, great ultimate tensile strength and low coefficient of thermal expansion (CTE). The Co-PIs-5 had lower crystallinity, lower CTE, greater elongation at break, higher Tg and thermal stability and the greater dense extent, compared with Co-PIs-3 and Co-PIs-6. Structure and property relations of the prepared polyimides were also briefly discussed. The results revealed that the copolymerization of s-BPDA/PDA with a small number of 4,4′-ODA/a-BPDA was a useful means for enhancing flexibility without sacrificing low CTE.

Thermal expansion behavior of polyimide films containing benzoxazole unit

2014 ◽  
Vol 26 (4) ◽  
pp. 413-419 ◽  
Author(s):  
Guangliang Song ◽  
Daming Wang ◽  
Guodong Dang ◽  
Hongwei Zhou ◽  
Chunhai Chen ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Polyimide Films ◽  
Thermal Expansion Behavior ◽  
Expansion Behavior

Optical Analysis of Porous Metal Bearings

1979 ◽  
Vol 101 (1) ◽  
pp. 99-104 ◽  
Author(s):  
K. M. Yung ◽  
A. Cameron
Keyword(s):  
Thermal Expansion ◽  
Metal Particle ◽  
Porous Metal ◽  
Optical Interferometry ◽  
Approximate Analysis ◽  
Optical Analysis ◽  
Oil Film ◽  
Order Of Magnitude

Optical interferometry is used to study the lubrication of porous bearings. The results suggest that thermal expansion in each metal particle causes it to act as a miniature tapered land bearing. An approximate analysis gives an order of magnitude for the tilt. All the evidence is against the existence of a continuous oil film round the bearing when used normally, which hitherto is the accepted model for the operation of these bearings. Micro-recirculation of the oil was observed and the importance of running-in is discussed.

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