PEEK-PEI blends

An intensively studied blend is the PEEK/PEI blend for which interlamellar [Chen and Porter,... 

Table 13.7 C-F parameters extracted from enthalpy relaxation data of PEEK/PEI blends (Hay 1992)...

Blends of PAEK and PEI can offer increased Tg, good chemical resistance at the lower PEI levels and reduced cost relative to pure PAEK. In particular PEI can be used to build the heat distortion temperature (HDT) of PAEK. Such blends find uses where PAEK-like performance is required in combination with an improved HDT. There are also applications in which the PEI is used above its Tg as a melt adhesive. For example, laminates of copper foil and PEEK/ PEI blend films can be produced in which the copper adheres to the hot, amorphous blend which subsequently crystallises to produce a chemical and solder-resistant structure. Mitsubishi has produced flexible printed circuit boards based on this concept [9]. 

Hydrophilic polymers such as poly (vinyl alcohol) or polyoxyethylene can be impregnated with a mineral acid and behave as solid proton conductors [119]. Several researchers [120] showed that polyethylenimine-sulfuric acid and phosphoric acid systems were well-behaved solid proton conductors under anhydrous conditions. Further information regarding these membranes is available in the literature [120]. Finally, Cakmak and Bicaksi [121] satisfactorily elaborated PEEK/PEI blend films. 

Cakmak, M., and Bicakci, S., 2002, Kinetics of rapid structural changes during eat setting of preoriented PEEK/PEI blend films as foUowed by spectral birefringence technique, Polymer 43 2737-2746. 

Blends of BPADA-based Pis are also miscible with polyaryl ether ketones such as polyetherether-ketone (PEEK). As injection molded, many PEEK-PEI blends are transparent. 

Ramani, R. and Alam, S., Composition optimization of PEEK/PEI blend nsing model-free kinetics analysis, Thermochim. Acta, 511 (1-2), 179-188 (2010) DOl 10.1016/j.tca.2010.08.012. 

To prepare the graft copolymer, a PO (MW = 50 to 1,000 kg/mol) was either dissolved or swollen in an inert hydrocarbon, monomers (>80 wt% of a methacrylic ester, CH2=C(CH3)COOR) and an initiator was added to the heated mixture while stirring. As a result, acrylic branches of a relatively high molecular weight (MW = 20 to 200 kg/mol) were grafted onto the PO macromolecules. The graft copolymer could be used as a compatibilizer-cwm-impact modifier in a variety of polymers selected from between PO, acrylic polymers, SAN, EVAc, PA, PEST, PC, POM, PAr, PVC, ABS, PVDC, cellulosics, polyester-polyether block copolymers, PEA, PEEK, PEI, PES, CPVC, PVDF, PPE, PPS, PSF, TPU, PAI, PCL, polyglutarimide, blends of PEST with PC or PVC [Ilendra et al., 1992, 1993]. 

PEEK/PEI Sample melt mixed at 400°C, quenched in ice water into 0.2-0.4 mm sheets. DSC (10 mg) at 20°C/min. Miscible blends. Goodwin and Simon, 1996... 

PEEK/PEI secondary crystallization melt blended and crystallized [Bassett et al., 1992 Hsiao and Sauer, 1994]... 

Table 12.16. Effect of immersion in acetone on the mechanical performance of amorphous PEEK, PEI and their 50/50 blend [Browne et al 1997]...

Poly(aryl ketones) (PEEK, PEK, and PEKK) are commercial high temperature polymers offering an excellent combination of properties combined with thermoplastic behavior. Poly(aryl ether ketone) PAEK blends have been reviewed by Harris and Robeson [1989]. Miscibility with PEI (Ultem 1000 GE) and other PI containing isopropylidene bridging units was noted. Arzak et al. [1997] reviewed the performance ofPEEK/PEI blends and noted a synergistic behavior in ductility and impact strength as reported earlier. Utility of these blends as a thermoplastic matrix candidate for advanced composites has been proposed [Harris and Robeson, 1989 Davis et al., 1992]. 

PEEK other blends PEEK/LCP PEEK/LTG PEEK/PEI... 

The inorganic low-temperature glasses (LTG) with Tg < 300 °C are durable and water resistant. LTG was blended with either PPS, PET, PBT, PEK, PEEK, PEI, LCP, PC, or fluorinated polymers (Prayer 1993, 1994). 

An intensively studied blend is the PEEK/PEl blend for which interlameUar (Chen and Porter 1994), interfibrillar (Crevecoeur and Groeninckx 1991 Hsiao and Sauer 1993), and interspherulitic segregations (Crevecoeur and Groeninckx 1991) were reported. In PEKK/PEI blends, PEI is segregated interspherulitically (Hsiao and Sauer 1993). 

Enthalpy relaxation studies have also been used to assess the aging of polyether ether ketone blends with polyetherimide, PEEK/PEI = 50/50 (Hay 1992). The preparation of the blend produced an amorphous system with Tg 215 °C, but crystallization of the PEEK occurred after raising the temperature above Tg. Data could only be collected in the temperature range Tg to Tg — 50) and no aging could be detected at temperatures below 150 °C (Table 13.7). The enthalpic relaxation data were analyzed using the C-E model and fits )delded values of p = 0.4, intermediate between those of the pure polymers. It was noted that values of p were higher than those obtained from dielectric relaxation measurements (0.1-0.22). This technique probes the dipole relaxation spectmm, and the lower... 

Xixian Zhou and M. Cakmak. "Influence of composition and annealing on the structure development in biaxially stretched PEN/PEI/PEEK ternary blends." Polymer, pp. 6362-6378,2006. 

There are also situations in which PEI has been used to compatabilise PAEK with other PEI-miscible polymers. For example, PEN/PEI/PEEK ternary blends have been biaxially stretched [10,11]. PEI is miscible with PEN and the PEEK is added to enhance the crystallisability of the blend and create a strain-hardening material. PEI has also been used to enhance the compatability of PEEK and polyethersulfone (PES) [12]. The PES can be encapsulated in a PEEK/PEI phase which further reduces the required amormt of PAEK. 

Nemoto, T., J. Takagi, and M. Ohshima. 2010. Nanocellular foams-cell structure ditference between immiscible and miscible PEEK/PEI polymer blends. Polymer Engineering Science 50 (12) (December30) 2408-2416. doi 10.1002/pen.21766. http //onlinelibrary. wiley.eom/doi/10.1002/pen.21766/fuU. 

PEEK/PEI Thermo-oxidation of PEEK is enhanced by PEI.The highest is for 50 50 composition - recommended Miscible blends TGA up to 1100°C in airor Ar 177... 

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