Investigation of the kinetics of chemical imidization

Koton, M.M.; Мелешко, Т. К.; Kudryavtsev, V. V.; Nechayev, P.P.; Kamzolkina, Ye.V.; Богорад, Н. Н.

doi:10.1016/0032-3950(82)90334-3

Cited by 42 publications

(20 citation statements)

References 11 publications

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“…The retardation in cyclization speed is due to the decrease in the movability of molecular backbone chain. 37 The temperature must be raised over T g so that the thermal energy is sufficient to surmount the potential barriers for translational and rotational Figure 9 The dynamic scanning curves of ODPA-TDA-PI after converted from PAA with four isothermal curing. Figure 8 The comparison of imidization behavior between the ODPA-TDA and ODPA-SDA cured from polyamic acid into polyimide at 3508C isothermal curing by RPR.…”

Section: Imidization Behavior and Glass Transition Temperaturementioning

confidence: 99%

Thermal imidization behavior of aromatic polyimides by rigid‐body pendulum rheometer

Chiu

Cheng

2008

J of Applied Polymer Sci

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Two types of polyamic acid (PAA) precursors were synthesized via combining 3,3 0 ,4,4 0 -Oxydiphthalicdianhydride (ODPA) with 4,4 0 -thioetherdianiline (TDA) and 4,4 0 -sulfonyldianiline (SDA), respectively. Thermal gravity analysis (TGA), rigid-body pendulum rheometer experiment (RPR), and Fourier transform infrared (FTIR) spectroscopy were combined to analyze the thermal imidization processes from precursors PAA to polyimides (PI). This procedure provides the new PAA-PI system with new methods for observing the imidization behavior, thermal properties, and finding the optimization of processing conditions. The results of the TGA and FTIR imidization conversion analysis revealed that the PAA-PI systems synthesized with identical dianhydride and different diamines have distinct reaction temperature regions and reaction speed. The inductive effect of withdrawing and releasing group and the rigidity-flexibility of the molecular chain in the structure of molecular backbone chain influence the imidization reaction. We have seen from the RPR test results that the entire imidization reaction in every isothermal testing temperature reaches an equilibrium condition and completes the gradation reaction of each isothermal temperature within 20 min. Glass transition temperatures (T g ) of PIs increase with increasing the conversion rate from PAA into PI and the rigidity of molecular chain.

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Section: Imidization Behavior and Glass Transition Temperaturementioning

confidence: 99%

Thermal imidization behavior of aromatic polyimides by rigid‐body pendulum rheometer

Chiu

Cheng

2008

J of Applied Polymer Sci

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“…Ring closure proceeds via a second nucleophilic substitution reaction. Since the amide group is an ambident nucleophile, cyclisation can occur by two different pathways [92]: if the nitrogen atom attacks, the product is the isoimide; if the oxygen atom attacks, the product is the imide. Although both products are usually formed, the isoimide subsequently rearranges to the imide.…”

Section: Mechanism Of Chemical Imidisationmentioning

confidence: 99%

“…The majority of studies have been carried out on film samples. In order to avoid any effect from variations in film thickness, optical densities are usually normalised against an internal aromatic absorption band [63,64]. The bands at 1015 and 1500cm-1 appear to be the most satisfactory.…”

Section: Thermal Imidisation Of Poly( Amic Acids)mentioning

confidence: 99%

“…Poly(amic acids) can be converted to the corresponding polyimides at ambient temperature by treatment with mixtures of aliphatic carboxylic acid dianhydrides and tertiary amines [4,[91][92][93]. Acetic anhydride and pyridine or triethyl amine are normally used.…”

Section: Chemical Imidisation Of Poly( Amic Acids)mentioning

confidence: 99%

“…The kinetics of a model chemical imidisation system have recently been determined [92]. Films of poly[(4,4'-oxydiphenylene)pyromellitamic acid] were immersed in a 1: 1 molar mixture of acetic anhydride and pyridine in benzene at 20 to 65°C.…”

Section: Kinetics Of Chemical Imidisationmentioning

confidence: 99%

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Synthesis of aromatic polyimides from dianhydrides and diamines

Harris¹

1990

Polyimides

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Polyimides

Bryant

2006

Kirk-Othmer Encyclopedia of Chemical Technology

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Polyimides are a class of high performance polymers that contain an imide group, defined as an sp 3 nitrogen bonded to two adjacent carbonyls. This imide structure is most commonly found as part of a five or six membered ring. Aromatic polyimides are noted for their mechanical properties, chemical resistance and dielectric strength. They exist as thermoplastics and thermosets and are available in many formats. Polyimides are used as hot melt adhesives, matrix resins for composites, dielectric films, photoimageable coatings, flex circuits, foams, wire insulation, thin walled tubing, molding resins and high performance bushings and seals. Products that compete with polyimides for niche applications include aerospace epoxies (Dow, Ciba and Shell), cyanate resins (Dow), polysulfones (Solvay), filled polycarbonates and polyesters (Dow, Amoco and GE), polybenzimidazoles (Hoechst‐Celanese) and some high Tg filled phenolics. Although polyimides command a premium price, their versatility, reliability, and demonstrated performance makes them suitable use in high performance applications where failure and replacement costs are high.

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Investigation of the kinetics of chemical imidization

Cited by 42 publications

References 11 publications

Thermal imidization behavior of aromatic polyimides by rigid‐body pendulum rheometer

Thermal imidization behavior of aromatic polyimides by rigid‐body pendulum rheometer

Synthesis of aromatic polyimides from dianhydrides and diamines

Polyimides

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