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Preparation and Characterization of Low-K and Low Loss Porous Polyimide Films
권용구,이영동,이동주 한국고분자학회 2021 한국고분자학회 학술대회 연구논문 초록집 Vol.46 No.2
A series of novel porous polyimide films are synthesized based on various diamines and dianhydrides. Poly(amic acid)s of dianhydrides and diamines are synthesized for further chemical imidization and freeze drying. The samples are in the form of xerogels which exhibit excellent mechanical strength and thermal, chemical stability. By modifying the chemical structure of component monomers, the final polyimide films display low dielectric constant and loss even at high frequency regime. The shrinkage of films is effectively reduced by varying the composition of the monomers, which remains dielectric constant and loss low. The thermal, dielectric and mechanical properties, as well as morphology of the final xerogel films are characterized using TGA, TMA, SEM, AFM, UTM, and network analyzer.
권용구(Y.G.KWON),주원경(W.K.JU),송정일(J.I.SONG) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.5
The mechanical characteristics of AC4C Aluminum Casting Alloy were investigated by tensile test and impact test. Based on the tensile test's result, we found that the yield strength of a high speed was about 10% higher than that of a low speed test and the maximum rupture strain mostly occurred in low speed tensile test. The impact energy of curved surface specimen was higher than that of plane surface specimen that can be measured in impact test.