Acid strength imides

As a result, the acid strength of the proton is approximately equivalent to that of sulfuric acid in nonaqueous media. In view of the excellent miscibility of this anion with organic nonpolar materials, Armand et al. proposed using its lithium salt (later nicknamed lithium imide , or Lilm) in solid polymer electrolytes, based mainly on oligomeric or macro-molecular ethers. In no time, researchers adopted its use in liquid electrolytes as well, and initial results with the carbonaceous anode materials seemed promising. The commercialization of this new salt by 3M Corporation in the early 1990s sparked considerable hope that it might replace the poorly... 

The polyether imides show much better hydrolytic stability with little change in tensile strength after exposure to water at 100°C for 1 year. These materials also show exceptional resistance to mineral acids, and are unharmed by most hydrocarbons including gasoline (petrol) and oils. 

Flexible copper-clad laminates with nonthermoplastic polyimides were prepared in a two-step process entailing isolating the polyamic acid and then thermally imidizing to the corresponding polyimide. Plasma or thermal treatments of selected polyimides generated materials with excellent bonding strength when evaluated on laminated copper foil. 

Boric acid in conjunction with APP was reported in epoxy intumescent coating.30-31 Boric acid and its derivatives were used in phenolics to impart thermal stability and tire retardancy. For example, Nisshin steel claims the use of boric acid and aluminum trihydroxide (ATH) in phenolics for sandwich panel.32 It was also reported that the small amounts of boric acid (around 0.25% by weight) in polyether imide (PEI) and glass-filled and PEI can reduce peak HRR by almost 50% in the OSU Heat Release test for the aircraft industry.33 In applications where high modulus and high strengths are needed, boric acid can be added without the softening effects of other additives such as siloxanes. 

Coating the inner wall of a silicic acid capillary chromatography column with a poly(ester-imide) is known. After curing the stationary phase is applied. Claimed are improved mechanical strength, faster application of the stationary phase and better quality of the column [276]. 

Both polyamide-imide and polyetherimide have high heat distortion temperature, tensile strength, and modulus. Polyamide-imide is useful from cryogenic temperatures up to 260°C. It is virtually unaffected by aliphatic and aromatic chlorinated and fluorinated hydrocarbons and by most acid and alkali solutions. These polymers are used in high-performance electrical and electronic parts, microwave appliances, and under-the-hood automotive parts. Typical automotive applications include timing gears, rocker arms, electrical connectors, switches, and insulators. 

It is well known that polymers with condensed imide rings exhibit high thermal stability. Properties of the imide ring containing ACEC LXII (Scheme 78), cured with amines and with an acid anhydride, are given in Table 20. Acid anhydride cured epoxyimides reach the heat resistance of 190 °C, temperature of the start of decomposition above 265 °C and flexural strength above 70 MPa. 

The Torlon materials produced by Amoco Chemicals are polyamide-imides of the type shown in Figure 4.20a. Torlon has high strength, stiflEness, and creep resistance, shows good performance at moderately high temperatures, and has excellent resistance to radiation. The polymers are unaffected by all types of hydrocarbons (including chlorinated and fluorinated products), aldehydes, ketones, ethers, esters, and dilute acids, but resistance to alkalis is poor. 

A poly(imide-siloxane)/titania hybrid film was fabricated by a sol-gel process by the in situ formation of titania within the poly(imide-siloxane) matrix [85]. The poly(amic acid siloxane) polymer was prepared from 4,4 -oxydiphthalic anhydride, 2, 2-bis [4-(4-aminophenoxy) phenyl] propane, and a,a>-bis(3-aminopropyl)polydimethylsiloxane. Acetylace-tone was used as chelating agent in order to reduce the rate of hydrolysis of titanium alkoxide in the polymer. The presence of titania on the surface of eventually produced films enhances the adhesive strength at the interface. 

---