Synthesis and characterization of polyimides containing 4,4'-hexafluoroisopropylidene-bisphthalic

Daniel Liu Chun Hung,Der-Jang Liaw,Tong-Ing Ho,Been-Yang Liaw

doi:10.1590/s0104-14281999000400013

Abstract

This paper presents the synthesis and characterization of polyimides, which contain a 4,4'-hexafluoroisopropylidene-bisphthalic anhydride (6FDA) unit in the backbone. These polyimides are a result of the use of the traditional method of one step. The reactions occur between equimolar of a dianhydride and an aromatic diamine in presence of the solvent dimethylacetamide (DMAc), then cyclo-dehydrided by adding the acetic anhydride and pyridine. In this work, the 6FDA was used as the dianhydride and four different diamines were investigated: 3,3',5,5'-Tetramethyl-2,2- bis[4-( 4-aminophenoxy) phenyl] propane; 2,2-bis[4-(4-aminophenoxy)-phenyl] hexafluoropropane; 1,3-bis(4-aminophenoxy)benzene and 2,2'-dimethyl-4,4'-bis(4-aminophenoxy)biphenyl. The four polyimides (PA, PB, PC and PD) were characterized by tensile strength, infrared, inherent viscosity, Differential Scanning Calorimeter (DSC) to get the glassy transition temperature (Tg) and Gel Permeation Chromatograph (GPC) to obtain the average molecular weight (Mn).

Highlights

T hexafluoroisopropylidene-bisphthalic anhydride (6FDA) unit in the backbone
The 6FDA was used as the dianhydride and four different diamines were investigated: 3,3’,5,5’-Tetramethyl-2,2- bis[4-( 4-aminophenoxy) phenyl] propane; 2,2-bis[4-(4-aminophenoxy)-phenyl] hexafluoropropane; 1,3-bis(4-aminophenoxy)benzene and 2,2’
This paper presents the synthesis and chabe seen, such as components of cable insulation, racterization of polyimides containing 6FDA unit in Daniel Liu Chun Hung, CTMSP-Centro Tecnológico da Marinha em São Paulo, Av

Summary

Introduction

T hexafluoroisopropylidene-bisphthalic anhydride (6FDA) unit in the backbone. These polyimides are a result of the use of the traditional method of “one step”. An aromatic diamine in presence of the solvent dimethylacetamide (DMAc), cyclo-dehydrided by adding the acetic anhydride and pyridine. The four polyimides (PA, PB, PC and PD) were characterized by tensile strength, infrared, inherent viscosity, Differential Scanning Calorimeter (DSC) to get the glassy transition temperature (Tg) and Gel Permeation Chromatograph (GPC) to obtain the average molecular weight (Mn).

Results

Conclusion