3 years ago

New poly(amide-imide)s with trifluoromethyl and chloride substituents: Synthesis, thermal, dielectric, and optical properties

New poly(amide-imide)s with trifluoromethyl and chloride substituents: Synthesis, thermal, dielectric, and optical properties
Two novel fluorinated diimide-diacid monomers, [2,2′-(4,4′-(4′-chloro-3′-(trifluoromethyl)biphenyl-2,5-diyl)bis(oxy)bis(3-(trifluoromethyl)-4,1-phenylene))bis(1,3-dioxoisoindoline-5-carboxylic acid)] (III) and [2,2′-(4,4′-(3′,5′-bis(trifluoromethyl)biphenyl-2,5-diyl)bis(oxy)bis(3-(trifluoromethyl)-4,1-phe-nylene))bis(1,3-dioxoisoindoline-5-carboxylic acid)] (IV), were respectively designed and synthesized viathe reactions between the diamine (I or II) and two molar equivalents of trimellitic anhydride. Based on these two diimide-diacids, two families of novel poly(amide-imide)s (PAIs) (IIIa–IIIe and IVa–IVe) bearing different trifluoromethyl groups were prepared by directly polymerizing diimide-diacids with a series of aromatic diamines (a–e). All of the PAIs exhibited high glass transition temperatures (T gs, 236–268°C), excellent thermal stability (only 5% weight loss at 493–542°C under nitrogen) and good solubility in various organic solvents since the bulky pendant groups were introduced. The cast films of these PAIs (thickness=80–90μm) had excellent optical transparency (70–83% at 450nm, 85–87% at 550nm and 88–89% at 800nm) and low dielectric constants (2.62–2.92 at 1MHz). In addition, the spin-coated films of these PAIs presented very low birefringence values the minimum of which was 0.0073 at 650nm. These spin-coated films also exhibited very weak absorption at the near-infrared communication wavelengths of 1310 and 1550nm.

Publisher URL: www.sciencedirect.com/science

DOI: S0014305717308832

You might also like
Never Miss Important Research

Researcher is an app designed by academics, for academics. Create a personalised feed in two minutes.
Choose from over 15,000 academics journals covering ten research areas then let Researcher deliver you papers tailored to your interests each day.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.