Functionalized Poly imide

Materials built up according to this concept exhibit low melt viscosities. They are stable for several hours at 210-275°C. The thermal curing of the phenylethynyl group does not occur to any appreciable extent at tem- 

3-phenylene)bis(4-phenylethynylphthalimide PEPA-m-phenylenediamine (MPD) A -[4-(3-phenoxy)-4 -phenylethynylbenzophenone]4 -phen-ylethynylphthalimide PEPA-APDE 248 

Phenylethynyl terminated imide (PETI) monomers can be used as reactive diluents for in melt processable PETI oligomers. Melting points of such monomers are shown in Table 15.3. 

The viscosities of the PETI oligomers can be reduced by blending them with the PETI monomers. The oligomers have molecular weights in the range of 2,000-5,000 Dalton. 

In Pis based on the dianhydrides 4,4 -BTDA and 3,3, 4,4 -biphenyl dianhydride (4,4 -BPDA), those that are terminated with 4-(l-phenylethynyl) 1,8-naphthalic anhydride (PENA) show superior properties in comparison to PEPA. Oligomers derived from PENA can be cured at lower temperatures and the corresponding cured polymers exhibit a better hydrolytic stability than those of PEPA. 

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This observation is further dramatized by some rather limited isothermal measurements on selected films (TABLE III). This data is typical of the metal ion filled BTDA + p,p -DABP poly-imides which we have examined. No changes in chemical functionality in the polyimide-metal film were apparent as judged by infrared spectral comparisons of polyimide alone and polyimide plus metal regardless of the metal employed. 

The selective dense layer of hydrophilic membranes is made from different polymers with a high affinity for water. These polymers contain ions, oxygen functions like hydroxyl, ester, ether or carboxylic moieties, or nitrogen as imino or imi-do groups. Preferred hydropilic polymers are polyvinylalcohol (PVA) [32], poly-imides, cellulose acetate (CA) or natural polymers like chitosan [33] or alginates. Organophilic membranes usually consist of crosslinked silicones, mostly polydimethyl siloxane (PDMS) or polymethyl octyl siloxane (POMS). 

Oxydianiline was separately mixed with 2,6-diaminopyridine and 3,5-diamino-1,2,4-triazole, to form a mixture of diamines. Then poly-(imide)s (PI)s were synthesized by reacting the mixture of the diamines and pyromellitic dianhydride. The adhesion strength of sputter-deposited copper to PI films is proportional to the content of functional groups." ... 

In 1951, Flory reported the condensation reaction of diacid chlorides, e.g. with potassium salts of imides, e.g. the condensation of sebacyl chloride with potassium phthalimide. In this way, A -acyl diimides are formed. Flory pointed out the possibility of forming polymers, when components with higher functionality are used. Poly(imide)s (PI)s from pyromeUitic acid were reported in 1955 by Edwards and Maxwell at DuPont. Tbe diamines used were of aliphatic nature. Later, in addition, aromatic diamines were used. The two major types of Pis are ... 

The pol5mier of an alignment layer may be a poly(imide), which is spin-coated from solution. After drying, a film with a thickness of 0.1 jtt is formed at 200°C. This film is subsequently rubbed in one direction so that it functions as the alignment layer. 

Govindaraj B, Sarojadevi M. Synthesis and characterization of poly (imide-benzimidazole) hybrid nanocomposites using nano-cluster of octa-amino functionalized polyhedral oligomeric silsesquioxane. Polym Compos 2013 34(6) 825-33. 

In a considerably different application, nanofabricated polyhnide surfaces can be useful for the preparation of cell spheroids, roughly spherical masses composed of cells and associated ECM that demonstrate tissue-hhe morphological and physiological functions. Cell culture on nanostructured ffuorinated poly-imides results in fibroblast cell spheroids with a density comparable to tissue in vivo, fostering interest in their development for tissue engineering applications [90]. 

For the purpose of discussing mesophase formation in polymers it is conveiuent to partition the polymers into two categories and introduce abbreviations that refer to these categories. Polymerized liquid crystals, here abbreviated PLCs, are derived from known, low molecular weight monomer liquid crystals (MLCs) that contain polymerizable functionality (e.g. vinyl units). We designate liquid-crystalline polymers (LCPs) to be semiflexible, linear polymers that are structurally related to conventional engineering thermoplastics, i.e. polymers derived from poly(ester)s, poly(amide)s, poly(imide)s, etc. We will examine the attributes of polymerized liquid crystals first, stressing the similarities between their properties and those of MLCs. 

Describe the fabrication and function in at least one E/0 application of waveguides fabricated from a poly(diacetylene) and a ladder CP. Compare its expected performance parameters with those of Li niobate and poly(imides). 

Wang, G., Weng, Y., Chu, D., Xie, D., Chen, R. (2009) Preparation of alkaline anion exchange membranes based on functional poly(ether-imide) polymers for potential fuel cell applications. Journal of Membrane Science, 326, 4—8. 

Morikawa et al. (79) later prepared poly(imide)-silica hybrids using polyamic acids synthesized from PMDA, ODA and other diamines. These diamines contained hydrolizable functions, enabling the formation of a chemically interconnected organic/inorganic network. In a sol-gel reaction with TEOS these PAA s formed transparent materials over a wide range of silica compositions. SEM micrographs indicated a silica domain size of 1 to 1.5 microns. 

Wang, G. Weng, Y Zhao, J. Chen, R. Xie, D., Preparation of a functional poly(ether imide) membrane for potential alkahne fuel cell applications Chloromethylation. Journal of Applied Polymer Science 2009, 772(2), 721-727. 

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