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Preparation and Characterization of 4,4′‐Bis(4‐aminophenoxy)diphenyl Sulfone Based Fluoropoly(ether‐imide)/Organo‐Modified Clay Nanocomposites
Author(s) -
Vora Rohit H.,
Pallathadka Pramoda K.,
Goh Suat Hong,
Chung TaiShung,
Lim Yong Xiong,
Bang Toong Kiang
Publication year - 2003
Publication title -
macromolecular materials and engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.913
H-Index - 96
eISSN - 1439-2054
pISSN - 1438-7492
DOI - 10.1002/mame.200390027
Subject(s) - materials science , thermal stability , nanocomposite , polyimide , montmorillonite , imide , contact angle , ether , polymer chemistry , absorption of water , glass transition , diphenyl ether , curing (chemistry) , composite material , chemical engineering , polymer , organic chemistry , chemistry , layer (electronics) , engineering
A series of fluoropoly(ether‐imide) (6F‐PEI), and [6F‐PEI/montmorillonite (MMT) clay) nanocomposites films were made by thermal curing of respective formulations containing fluoropoly(ether‐amic acid) (6F‐PEAA), synthesized from 2,2′‐bis(3,4‐dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) and 4,4′‐bis(4‐aminophenoxy)diphenyl sulfone ( p ‐SED), and increasing concentration of p ‐SED treated montmorillonite clay (modified MMT clay) at temperature from RT to 350 °C. These films showed excellent solvent resistance as well as very good thermal stability, and increased glass transition ( T g ) values with increasing % clay. In addition, these trifluoromethyl groups‐containing nanocomposites films showed sharp lowering of coefficient of thermal expansion (CTE) by 22%. Furthermore, they exhibited increased long‐term thermo‐oxidative stability (TOS), with % weight retention in the range of 86 to 92% in isothermal heating at 300 °C for 300 h in air, reduced water absorption at 100 RH at 50 °C in the range of 0.5 to 1.15%. These data are still much lower than those of neat ULTEM® 1000 and Kapton® H film. The modulus of elasticity is on an average 38% higher for the nanocomposite films relative to neat fluoropoly(ether‐imide) (6FDA + p ‐SED), and above non‐fluorinated polyimide films. The surface energy measurement by One‐Liquid and Two‐Liquid method showed a comparable trend of decreasing contact angle. For the nanocomposite films having 15% hydrophobic clay, the contact angle decreased by 21 and 20% for DI‐water and formamide, respectively. The surface energy increase was in the range of 8.21–8.54 mJ/m 2 .