Comparative study of silicon‐containing polyimides from different oxydianilines

Abstract

Silicon-containing polyimides were synthesized by solution polycondensation of bis(3,4-dicarboxyphenyl)dimethylsilane dianhydride with 3,4-oxydianiline and 4,4Ј-oxydianiline, respectively. All the poly(amic acid) films could be obtained by solution-casting from N,N-dimethylacetamide solutions and thermally converted into transparent and tough polyimide films. The physical properties of thin films of those polyimides were compared by DSC, TGA, UV-visible spectroscopy, and dynamic mechanical analysis. The polyimide from bis(3,4-dicarboxyphenyl)dimethylsilane dianhydride and 3,4-oxydianiline exhibited superior energy-damping characteristic, mechanical properties, and optical transparency, whereas that from bis(3,4-dicarboxyphenyl)dimethylsilane dianhydride and 4,4Ј-oxydianiline possessed higher glass-transition temperature and thermal stability. Because of the unsymmetric structure of the polyimide from bis(3,4-dicarboxyphenyl)dimethylsilane dianhydride and 3,4-oxydianiline, its increasing rate of linear coefficient of thermal expansion with temperature was quicker than that of the polyimide from bis(3,4-dicarboxyphenyl)dimethylsilane dianhydride and 4,4Ј-oxydianiline.

Stereoselective Convergent Synthesis of 24,25-Dihydroxyvitamin D3 Metabolites: A Practical Approach

“…The films of PI‐10 and PI‐15 exhibit broader α relaxation peaks. The magnitude of tan δ at T g is related to the impact strength24 which increases with the increase of tan δ value at T g . The value of tan δ at T g for PI‐0 is about 1.002; however, that for PI‐15 is only about 0.420.…”

The effect of zeolite L content on dielectric behavior and thermal stability of polyimide thin films

“…The magnitude of the tand at T g is related with the impact strength of a material. The impact strength increases with the addition of tand value at T g [48]. The results indicated that the energy-damping characteristics and mechanical properties of the composites did not decrease with the increase of zeolite L content.…”

Structuring and characterization of a novel highly microporous PEI/BMI semi-interpenetrating polymer network

“…However, the decrease in the intensity of this peak in spectra of PEI-BMI-EtOH (S and L) might be attributed to imide cleavage. The shoulder peak at 1216 cm K1 labeled (f) and the peak at 1240 cm K1 labeled (g) were reported to be twin peaks [39] and could be assigned to asymmetric stretching in diarylether (Table 4) [26,40]. The peak (f) was observed to shift to a lower frequency (1211 cm K1 ) with an increase in the intensity for PEI-BMI-EtOH (S and L) spectra.…”