Degree of imidization for polyimide films investigated by evolved gas analysis-mass spectrometry

Kim, Byoung-Hyoun; Park, Huijung; Park, Heeyong; Moon, Dong Cheul

doi:10.1016/j.tca.2012.10.029

Cited by 14 publications

(8 citation statements)

References 18 publications

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“…PAA solutions were prepared by adding the equimolar amount of dianhydrides into the N , N ‐dimethylacetamide solution of diamines according to a procedure of previous report . PAAs consist of BPDA, ODA, and PDA for PAA‐1, BPDA, PMDA, BTDA, ODA, and PDA for PAA‐2, BPDA and PDA for PAA‐3, and BPDA, PMDA, BTDA, and PDA for PAA‐4.…”

Section: Methodsmentioning

confidence: 99%

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Monomer Determination of Polyamic Acids by Hydrolysis and Methanolysis, and Gas Chromatography–Mass Spectrometry

Kim

Cho

2016

Bulletin Korean Chem Soc

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Polyimides (PIs) have attracted attention because of their excellent thermal stability, high mechanical properties, and good chemical resistance. 1 Hence, they have been widely used in many applications such as aerospace, microelectronics, and optoelectronics. [2][3][4][5] As most PIs are insoluble except soluble PIs, they are often formed by two-step processes involving the synthesis of polyamic acid (PAA) as a precursor of PI, followed by thermal dehydration of the amide-acid to form PI. In addition, PAA are formed by the condensation reaction of a diamine and a dianhydride in a polar aprotic solvent. 4,6 Many articles have been reported for the thermal behavior of PI film, 4,7 the surface modification of PI, 3,8 the fabrication analysis, 9,10 and the degree of imidization, 11,12 respectively. In general, PIs provide wide variations in technical properties according to their chemical structures. Therefore, it is important to achieve an adequate analytical method for the compositional analysis in manufacturing and benchmarking of PAAs.The analytical method has been studied and reported for the pyrolytic methylation of organic acids, 13,14 the hydrazinolysis for the cleavage of PI and the derivatization of monomers, 15,16 and the hydrolysis of PIs. 17 In this study, we describe a simple method for the determination of the monomer composition of PAAs. A gas chromatography/mass spectrometry (GC/MS) method using hydrolysis and methanolysis as the sample pre-treatment procedure was used to analyze diamine and dianhydride components of PAAs. In addition, results obtained from pyrolysis-GC/MC with tetramethylammonium salt as a derivatization reagent (React Py-GC/MS) were compared with the data from GC/MS method.To analyze the chemical composition of PAAs by GC/MS, hydrolysis and methanolysis were first performed for the cleavage of polymer chain and derivatization of the monomer. The overlaid total ion chromatogram (TIC) derived from GC/MS is shown in Figure 1, and the chemical structures identified are given in Table 1. A PAA can decompose into small molecules by treatment with sodium hydroxide for hydrolysis and acid-catalyzed methanol for methanolysis. Consequently, diamines and tetracarboxylic acid sodium salts were produced by hydrolysis, and ammonium sulfates of corresponding diamines and methyl esters of tetracarboxylic acid were produced by methanolysis. p-Phenylenediamine (PDA) and 4,4-oxydianiline (ODA) were detected as the diamine compounds from the hydrolysates of PAA-1 and PAA-2, and PDA was only detected in the hydrolysates of PAA-3 and PAA-4. After hydrolysis, all diamines detected were in the free form as monomers of PAA preparation. Hence, the analysis of hydrolysates was useful for the determination of the diamine composition of PAAs. In addition, any interfering components were absent in the GC/MS analysis. The tetracarboxylic acid compounds hydrolyzed from the polymer chain were converted to the corresponding carboxylic acid sodium salts in the basic hydrolysis solution. Thus, they were not extracte...

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Section: Methodsmentioning

confidence: 99%

“…Many articles have been reported for the thermal behavior of PI film, the surface modification of PI, the fabrication analysis, and the degree of imidization, respectively. In general, PIs provide wide variations in technical properties according to their chemical structures.…”

Section: The Chemical Structures In Figures Andmentioning

confidence: 99%

Monomer Determination of Polyamic Acids by Hydrolysis and Methanolysis, and Gas Chromatography–Mass Spectrometry

Kim

Cho

2016

Bulletin Korean Chem Soc

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“…Then, it was heated by a vacuum oven (Reale, Dongguan, China) in stages to elevated temperatures to further remove solvent and convert the amic acid functional groups to imides with a cyclodehydration reaction, the detailed thermal imidization procedure is shown in Figure S1 (Supplementary Materials, Figure S1). The rising and cooling process has been optimized according to the previous study [14][15][16] to ensure the fully imidization of co-PAI. In the current work, to ensure the optical uniformity of a large diameter co-PAI membrane for optical use, spin coating and thermal imidization procedure will be repeated three times.…”

Section: Preparation Of Copolyamide-imide Membranementioning

confidence: 99%

Copolyamide-Imide Membrane with Low CTE and CME for Potential Space Optical Applications

2021

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Polyimide diffractive membrane lens can be used in space optical telescope to reduce the size and mass of an imaging system. However, traditional commercial aromatic polyimide membrane is hard to meet the challenging requirements of dimensional stability and optical homogeneity for optical use. Based on molecular structure design and the optimization of fabrication process, the prepared copolyamide-imide membrane achieved the desired performance of membrane as an optical material. It showed a very low coefficient of thermal expansion (CTE), which is 0.95 ppm/°C over a temperature range of −150–100 °C and relatively low coefficient of moisture expansion (CME), which is only 13.30 ppm/% RH (0~90% RH). For the optical use, the prepared copolyamide-imide membrane (φ200 mm) achieved good thickness uniformity with wave-front error smaller than λ/30 (λ = 632 nm) in RMS (root mean square). Besides, it simultaneously meets the optical, thermal, and mechanical requirements for space telescope use. Copolyamide-imide membranes in this research with good comprehensive performance can be used as large aperture membrane optical system architectures.

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“…The unique chemical structure endues excellent resistance to high temperature (long‐term 250–300°C, short‐term 400–500°C) as well as high strength and modulus of PI materials . At the same time, it possesses the characteristics of space material with low vacuum volatiles and low volatile agglomerates . Therefore, PI is considered to be one of the most promising engineering materials in the 21st century , thus possesses broad application prospects and great commercial value in the aerospace, microelectronics, precision machinery, medical equipment, and other high‐tech fields .…”

Section: Introductionmentioning

confidence: 99%

Effect of Dibutyltin Dilaurate and Triethanolamine Catalysts on Structure and Properties of Polyimide Foams

Tian

Yao

Yin

et al. 2019

Vinyl Additive Technology

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A series of rigid polyimide (PI) foams were prepared by the prepolymer method with pyromellitic dianhydride and polyaryl polymethylene isocyanate as the starting materials and dibutyltin dilaurate (DBTDL), and triethanolamine (TEOA) as catalysts. The effect of the two kinds of catalysts on the structure and properties such as molecular structure, cell morphology, density, mechanical properties, thermal properties, and flame retardancy of the resulting foams were characterized in detail. The experimental results showed that the PI foams prepared in this work possessed low density, good mechanical properties, outstanding thermal stability, and excellent flame retardancy. The thermal stability and flame retardancy were improved obviously with the increase of DBTDL content. While with the increase of the content of TEOA, the mechanical strength and apparent density of PI foams increased significantly. Therefore, different structure and performance of PI foams can be prepared by adjusting the content of these two catalysts. J. VINYL ADDIT. TECHNOL., 25:385–395, 2019. © 2019 Society of Plastics Engineers

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Degree of imidization for polyimide films investigated by evolved gas analysis-mass spectrometry

Cited by 14 publications

References 18 publications

Monomer Determination of Polyamic Acids by Hydrolysis and Methanolysis, and Gas Chromatography–Mass Spectrometry

Monomer Determination of Polyamic Acids by Hydrolysis and Methanolysis, and Gas Chromatography–Mass Spectrometry

Copolyamide-Imide Membrane with Low CTE and CME for Potential Space Optical Applications

Effect of Dibutyltin Dilaurate and Triethanolamine Catalysts on Structure and Properties of Polyimide Foams

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