Synthesis and characterization of soluble and transparent co-polyimides with controlled glass transition temperature

Abstract

<span style="font-size:11.0pt;mso-bidi-font-size: 10.0pt;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="" lang="EN-US">Two dianhydrides, namely 4,4'-oxydiphthalic dianhydride and 2,2’-Bis[4-(3,4-dicarboxyphenoxy)phenyl] propane dianhydride, and one diamine (4,4’-Diaminodiphenyl sulphone), <span style="font-size:11.0pt; mso-bidi-font-size:10.0pt;font-family:" times="" new="" roman";mso-fareast-font-family:="" simhei;mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:="" ar-sa"="" lang="EN-US">have been<span style="font-size:11.0pt;mso-bidi-font-size: 10.0pt;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="" lang="EN-US"> used for the synthesis of a<span style="font-size:11.0pt; mso-bidi-font-size:10.0pt;font-family:" times="" new="" roman";mso-fareast-font-family:="" simhei;mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:="" ar-sa"="" lang="EN-US"> novel co-<span style="font-size:11.0pt;mso-bidi-font-size: 10.0pt;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="" lang="EN-US">polyimide with good solubility, high visible light transparency and high thermal stability. The solubility in several solvents of polyimides with different proportion of dianhydrides has been tested, and the glass transition temperature is determined by differential scanning calorimetry. The polyimide film has been prepared and the optical transmittance is mensurated. The polyimides solubility and light transmittance improved by introducing flexible monomer, and the glass transition temperature of the polyimides is well controlled by the content of 2,2’-Bis[4-(3,4-dicarboxyphenoxy)phenyl] propane dianhydride that has the flexible isopropylidene structure.</span></span></span></span></span>