Organosoluble and high polyimides from asymmetric diamines containing -amino and -aminophenyl naphthalimide moieties

• Published in: RSC advances 2016-03, Vol.6 (3), p.2532-2531
• Main Authors: Mushtaq, Nafeesa, Chen, Guofei, Sidra, Lala Rukh, Fang, Xingzhong
• Format: Article
• ISSN: 2046-2069
• DOI: 10.1039/c6ra00143b

To investigate the asymmetric effect of the naphthalimide moiety on the thermal, mechanical, optical properties and water uptake of polyimides (PIs), two novel asymmetric diamines, 4-(4-aminophenoxy)- N -amino-1,8-naphthalimide 3 and 4-(4-aminophenoxy)- N -(4-aminophenyl)-1,8-naphthalimide 4 were synthesized. Two series of PIs 5b-e and 6a-e were prepared from diamines 3 and 4 by solution polymerization method, respectively. The resulting polyimides demonstrated good solubility, high glass transition temperature ( T g ) of 311-421 °C and good thermal stability based on the 5% weight loss temperature ( T 5% ) of 435-563 °C in nitrogen. These PIs also exhibited good mechanical properties with tensile strengths of 107.3-172.2 MPa, tensile moduli of 2.8-4.9 GPa, and elongations at break of 2.9-9.1%. The water uptake of PIs was in the range of 0.33-1.96%. The polyimides displayed UV-vis absorption maxima and an intense fluorescent intensity in the range of 361-371 and 480-700 nm, respectively. Two series of polyimides derived from two asymmetric diamines are synthesised by different polymerization methods. The effect of asymmetry and non-coplanarity of two bisimides on the polymer properties is well investigated.