Preparation and Characterization of 4,4′‐Bis(4‐aminophenoxy)diphenyl Sulfone Based Fluoropoly(ether‐imide)/Organo‐Modified Clay Nanocomposites

Abstract

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 (Tg) 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/m2.

1,2′-Bis(4-aminophenoxy)benzene based designed fluoro-poly(ether-imide)/MMT clay nanocomposites: Synthesis and properties for high performance applications

“…Also the extraordinary large surface area of the exfoliated clay platelets provided strong interfacial interactions and increased adhesion with 6F-PEI polymer matrix. This nanometer size clay pellets distorted the linearity of polymer chains thereby reducing molecular chain rotation and inter-segmental motion of 6F-PEI polymer, thus providing less interchain slippage, and imparting rigidity and stiffness to the nanocomposite films [9,10,16,[21][22][23][24][25]30,31]. An interesting observation can also be made from the plot of modulus as a function of the concentration of organo-soluble MMT clay (Fig.…”

“…This would allow accommodation and insertion of the poly(amic acid) between ion exchanged clay galleries. We have used the procedure reported by Vora and co-workers [9,10,16] shown as part (a) of the synthesis scheme given in Fig. 1.…”

“…Exfoliation and homogenous distribution of nanometer size clay platelets, and embedding into the polymer matrix even in small extent can deliver the best performing polymer/MMT clay nanocomposites with dramatic enhancements of many materials properties, such as mechanical and thermal properties, general flame retardant character, insulating and barrier properties, chemical stability, etc. [6][7][8][9][10][11][12][13][14][15].…”

“…[16]. Table 1 Properties of (6FDA + p-SED) fluoro-poly(ether imide) 6F-PEI polymer films [9,10,16,17] Fluoro-poly ( Therefore, a proper modification of clay surface with specific organic amines and controlling the loading of such clays into the polymer matrix would allow tailoring of surface properties of polymer/MMT clay nanocomposite, such as, wettability, adhesion, polarity or surface charges, as well as tribological properties which are of particular interest in the microelectronics, biomaterial and biosensor fields. Such perfect 'Ceramer' materials with all the desired properties, based on 'polyimides' chemistry have not been developed or marketed yet.…”

“…However, it is expected that, if and when developed, these new materials would provide unique properties for potential applications in electronics (molding compounds, thermally stable alpha particle shielding film), automotives and aerospace (stronger, light weight, and high temperature stable structural components, as well as abrasion materials) industries. [9,10,16] These may also find use in life sciences (bio-materials for medical devices and sensors, or substrate materials to grow bio-enzymes or proteins molecules), separation membranes, MEMs, etc. Vora and coworkers [17] reported a detailed study of high-performance fluoro-poly(ether imide) (6F-PEI) polymers [6FDA + p-SED], having compositions based on 2,2-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride (6FDA) and 4,4 -bis(4-aminophenoxy)diphenyl sulfone (p-SED).…”