Poly imide applications

Mitsui Chemicals is launching a new grade of carbon nanotube reinforced thermoplastic poly-imide, Aurum CNT, with supplementary specific properties such as dust reduction and antistatic behaviour. Targeted applications are, for example, processing jigs for semiconductor or hard disk manufacturing, and parts for hard disk drives. 

Sulfonated poly(arylene ether)s have shown promise for durability in fuel cell systems, while poly-(styrene)- and poly(imide)-based systems serve as model systems for studying structure-relationship properties in PEMs because their questionable oxidative or hydrolytic stability limits their potential application in real fuel cell systems. Sulfonated high performance polymer backbones, such as poly(phe-nylquinoxaline), poly(phthalazinone ether ketone)s, polybenzimidazole, and other aromatic or heteroaromatic systems, have many of the advantages of poly-(imides) and poly(arylene ether sulfone)s and may offer another route to advanced PEMs. These high performance backbones would increase the hydrated Tg of PEMs while not being as hydrolytically sensitive as poly(imides). The synthetic schemes for these more exotic macromolecules are not as well-known, but the interest in novel PEMs will surely spur developments in this area. 

Addition poly(imide) oligomers are used as matrix resins for high performance composites based on glass-, carbon- and aramide fibers. The world wide market for advanced composites and adhesives was about 70 million in 1990. This amounted to approximately 30-40 million in resin sales. Currently, epoxy resins constitute over 90% of the matrix resin materials in advanced composites. The remaining 10% are unsaturated polyester and vinylester for the low temperature applications and cyanate esters and addition poly(imides) for high temperatures. More recently thermoplastics have become important and materials such as polyimides and poly(arylene ether) are becoming more competitive with addition polyimides. 

A great deal of literature attention has been devoted to polymers in this section as thermally stable polymers (B-80MI11101). While some very elegant syntheses have been conducted, the resulting polymers have been, for the most part, quite intractable materials not conducive to extensive screening for a variety of applications. Thus, aside from their bulk thermal performance, little else besides the conditions of synthesis is known about most of the polymers shown. Three notable exceptions about which considerable characterization and product information are available are poly(imides), poly(benzimidazoles) and poly(quinoxalines), and a short discussion is included concerning properties and applications of these polymers. 

The second approach has the advantage that it provides flexibility in the choice of means to perform the printing. Figure 10.14 shows a stamp with this construction, designed for plastic electronics applications [42]. It consists of a thin layer of PDMS on top of a sheet of polyimide. The relatively high in-plane modulus of the poly-imide prevents distortions that can frustrate registration. Its small thickness enables the stamp to be bent in a manner that facilitates printing. 

Poly(imides) contain the group -C(0)-NH-C(0)- in their structure. Many poly(imides) with practical applications have a more complicated formula and contain oxygen atoms and aromatic rings in the backbone [1]. One example is poly(pyromellitic dianhydride-a/f-4,4 -oxydianiline) or PMDA-ODA, CAS 25038-81-7, which is obtained from pyromellitic anhydride and oxybis(benzenamine) by water elimination as follows ... 

Some copolymers of poly(imides) found practical applications, typically due to their good thermal resilience. One such copolymer is poly(3,3, 4,4 -benzo-phenone-tetracarboxylic dianhydride-co-m-phenylene-4,4 -oxydianiline) with the structure indicated below ... 

An alternative route to the formation of poly(imide)s is the nitro-displace-ment reaction to form the Ultem series of polymers, first exploited by White et al. [11] at General Electric. These, and similar materials, have application in composite materials and as specialty thermoplastics. Compared to the amic acid route described above, the nitro-displacement reaction is highly controlled, and materials of high chemical regularity produced, as demonstrated by White et al. [11] in their solution-state NMR study of Ultem poly(imide)s. 

For passivation applications,the use of the ultrapure polyamic acid involves some changes in the routine processing. The poly-imide passivation process consisted of the following steps ... 

Different thermally induced cross-linking approaches have been investigated, such as the formation of sol-gel networks [93,94] or reactions resulting in poly-imides [95] and maleimides [96]. Thermoset PU have been widely studied for EO applications [92,97]. Zhang et al. synthesized a high /i/Lderived isophorone-derived... 

On carbon films prepared fi om commercially available poly(imide) films with a thickness of 0.1 mm, selective permeation of hydrogen gas was recently found [105]. This permselectivity may help to develop applications of these carbon films in fuel cells for vehicles, since CO in H2 gas supplied from an on-board reformer has to be removed through a molecular sieving membrane. 

Although poly(imide)-coated FS accounts for the vast majority of applications in CE, polymeric materials have also been studied as materials for CE capillaries since these offer a variety of different... 

Poly(amide imide)s (PAI)s have been used in the late 1960s as wire coating materials.Soon afterwards this class of polymers were considered for aerospace applications." Varieties with urethane units and ester units have been discussed. Now various grades, suitable for extrusion and injection molding are available. Thermosetting types are also on the market. PAIs are in between poly(amide)s (PA)s and poly(imide) (PI) in their properties. 

Polyanhydrides have been developed into various systems with mainly bone tissue engineering applications in mind. These polymers have mechanical strength much lower than that of bone but have been combined with other polymers, such as poly(imide)s, to resolve this problem. Polyanhydrides have been developed into photo-cross-linkable systems, based on dimethacrylated anhydrides, and also injectable systems, but little interest into these polymers with regard to tissue engineering has been taken in the recent past [82]. 

MTR, Inc. has also developed another commercial PV application using silicon rubber coated on microporous poly-imide support membranes for the separation of dissolved volatile organic compound (VOC) from water, achieving very high separation factors for toluene, benzene, chlorinated solvents, esters, and ethers. 

Srisuwan S, Ding Y, Mamangun D, Thongyai S, Praserthdam P, Sotzing GA, et al. Secondary dopants modified PEDOT-sulfonated poly (imide)s for high-temperature range application. J Appl Polym Sci 2013 128(6) 3840-5. 

Sukchol K, Thongyai S, Praserthdam P, Sotzing GA. Effects of the addition of anionic surfactant during template polymerization of conducting polymers containing pedot with sulfonated poly(imide) and poly(styrene sulfonate) as templates for nano-thin film applications. Synth Met 2013 179 10-7. 

Lin CC, Chang CB, Wang YZ. Preparation and properties of cross-linked sulfonated poly(imide-siloxane) for polymer electrolyte fuel cell application. J Power Sources 2013 223 277-83. 

Sasaki, Sh., Tega, E., Shimada, A. et al. 2003. Basic characteristics of hoUow-filament poly-imide membrane in gas separation and application to tritium monitors. 

Polypropylene is generally used as oriented polypropylene. Polyvinyl chloride film is commonly used in plasticized form. Polyvinylidene chloride is often known as Saran and is generally used in copolymer form with acrylonitrile. Polyethylene terephthalate is a thermoplastic polyester. Polystyrene is sometimes used in biaxially oriented form. Polycarbonates, polysulfones, polyether sulfones, poly-imides, polyetherimides, and several fluoropolymers are also used for specialty applications. 

The incorporation of a polysiloxane component in poly(imide)s imparts a number of useful properties to the polymeric system, including enhanced solubility good thermal, oxidative, and ultraviolet stability reduced water uptake and modified surface properties. Because of these advantages, polysilox-ane-modified polyimides draw attention in the fields of aerospace, microelectronics, gas separation, and other high-performance applications. 

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