Highly transparent polyimides derived from 2-phenyl-4, 6-bis(4-aminophenoxy)pyrimidine and 1, 3-bis(5-amino-2-pyridinoxy)benzene: preparation, characterization, and optical properties. Issue 125 (8th December 2015)

• Record Type: Journal Article
• Authors: Wang, Chunbo; Guan, Yue; Tian, Dongbo; Dang, Guodong; Wang, Daming; Chen, Chunhai; Zhou, Hongwei
• Is Part Of: RSC advances. Volume 5:Issue 125(2015)
• Page Start: 103246
• Page End: 103254
• Publication Date: 2015-12-08
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c5ra19167j
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Heterocyclic polyimides were prepared from two novel diamines with anhydrides, which exhibit outstanding solubility and optical transparency properties. Abstract : To investigate the structure–property relationships of polyimides containing pyrimidine or pyridine moieties, two diamine monomers, 2-phenyl-4, 6-bis(4-aminophenoxy)pyrimidine and 1, 3-bis(5-amino-2-pyridinoxy)benzene, were designed and synthesized. The diamines reacted with different commercially available aromatic dianhydrides to yield a series of heterocyclic polyimides via a classical two-step polymerization method. The polyimides, PI-1 and PI-6, exhibited excellent solubility in strong polar solvents, such as N, N -dimethylacetamide, N, N -dimethylformamide and N -methyl-2-pyrrolidone. The flexible, strong and transparent polyimide films were formed with UV-visible absorption cut-off wavelengths at 344–399 nm. Glass transition temperatures ( T g ) of the polyimides PI-(1–6), derived from PBAPD and BADB with dianhydrides, in the range of 212–260 °C were obtained by DSC, and the temperatures for 5% wt loss of the polyimides in nitrogen and air atmospheres were obtained from TGA in the range of 430–503 °C and 422–465 °C, respectively. Moreover, the polyimide films showed a low moisture absorption of 0.18–1.38% and outstanding mechanical properties with tensile strengths of 81–111 MPa, an elongation at break of 4.3–8.7%, and a tensile modulus of 1.3–2.4 GPa. The coefficients of thermal expansion (CTEs) of the polyimides ranged from 28 to 62 ppm °C −1 .