Imide polymer blends

In order to control the pore texture in carbon materials, blending of two kinds of carbon precursors, the one giving a relatively high carbonization yield and the other having a very low yield, was proposed and called polymer blend method [112], This idea gave certain success to prepare macroporous carbons from poly(urethane-imide) films prepared by blending poly(amide acid) and phenol-terminated polyurethane prepolymers [113]. By coupling this polymer blend method with... 

As a final example of the use of proton NMR invoking spin diffusion to study miscibility of polymer blends, the use of CRAMPS to remove proton dipolar coupling in a blend of an aromatic poly(ether-imid) (PEI), and a poly(aryl-ether-ketone) (PEEK), with detection of the magnetization of the C in the blend under high resolution conditions is cited [51]. Here, detailed information on the chemical composition of the phases present, as inferred from high resolution NMR of C, is linked to typical sizes of domains as reflected in spin diffusion of proton magnetization. 

Solid-state NMR has been applied successfully in a few cases for the study of poly(imide) blends. It can be said, however, that the techniques arising from recent advances in the analysis of polymer blends, such as selection techniques based on multipulse methods, and improvements in the modelling methods of spin diffusion, have yet to be applied to the study of blends containing poly(imide)s. It is suggested that these techniques will have an important role to play in future studies of poly(imide) blends, particularly for blends such as impact-modified BMI resins. 

Additional polymer blends comprising PAEK s offering property combinations of potential utility include PSF [Robeson and Harris, 1986 Harris and Robeson, 1989] structurally different poly(aryl ketones) [Harris and Robeson, 1986], PAr [Robeson and Harris, 1992], poly(amide-imide) PAI [Harris and Gavula, 1992], PPS [Robeson, 1987], and other PI [Harris et al., 1992]. Mixtures of structurally different PAEK s were noted to be isomorphic within specific limits of ether/ketone ratios [Harris and Robeson, 1987]. Blends of polybenzimidazole, PBI and several commercial PI (Ultem 1000 and Matrimid 5218) have been studied in depth at the University of Massachusetts and found to be miscible. FTIR studies [Guerra et al., 1988 Kim et al., 1993], NMR studies [Grobelny et al., 1990], thermal, dielectric, and mechanical... 

Glassy polymeric materials are often plasticized when used in gas membranes due to sorption. This can be overcome by annealing or crosshnking, however, this method does not influence the selectivity of the membrane, instead the permeability is decreased. Another method to stabilize the plasticization is to use polymer blends, as demonstrated with Matrimid 5218 and a copoly(imide) P84. The material is stabilized against carbon dioxide plasticization and the selectivity for a mixture of carbon dioxide and methane is improved. Hollow fiber membranes composed of blends of Pis with enhanced resistance towards hydrocarbons have been developed. ... 

Polyamide-imide polymers find application in hydraulic bushings and seals, mechanical parts for electronics, and engine components. The polymer in solution has application as a laminating resin for spacecraft, a decorative finish for kitchen equipment, and as wire enamel. Low coefficient of friction materials may be prepared by blending PAI... 

There are some newer application areas and polymer blend products targeted to fit those new opportunities. The latter include such combinations as PVC and PS blended with PP, HOPE, and each other metallocene-polymerized nanoscale blends of polyolefins with more polar polymer partners and, for high-temperature/high-performance applications, PPS blended with PSF, PEI, and polyamides as well as blends incorporating poly(aryl ketones), polyimides, and poly(amide-imides) (Thomas et al. 2006). 

As a third component, polysulfone (PSF) Udel P-17(X) of Amoco was tested for PPS/LCP blend, and three kinds of newly designed imide polymers, polyetherimide (PEsI), PET/PEsI block copolymer (BHETI), and PBT/PEsI block copolymer (BHBTI), were tested for PEI/LCP blend. The three compatibilizing agents, PEsI, BHETI and... 

Table 3.1 Examples of Reactively Compatibilizcd Polymer Blends Making Use of Imidization In Situ Reactions...

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