PEKK, amorphous

PEKK is produced from diphenylether and phthaloyl chlorides [19]. It is one of the few PAEK that would be difficult to make by nucleophilic routes because of the obvious complexity of the monomer required. The high melting point of linear, 100% para PEKK means that commercial PEKK is actually made from both terphthaloyl (T) and isophthaloyl chloride (I). Crystalline PEKK is typically 80 20 T/I whereas the amorphous grades used for thermoforming are 60 40 T/I. 

Inside aircraft the fire, smoke and toxicity performance of PAEK is often their key advantage versus other plastics. PAEK produce relatively little smoke and toxic gas in fire situations and they are used extensively in cabin structures. Polyaryletherketoneketone (PEKK) (often laminated with Tedlar) is used to make thermoformed cabin interior panels. Amorphous PEKK has the advantage of being thermoformable at relatively low temperatures which are compatible with polyvinylidene fluoride (PVDF) and the various adhesives used in the laminate. PEEK is found in window surrounds, passenger service units and lamp housings. Glass fibre-reinforced PEEK is used in the... 

Finally test and burn in sockets must be able to survive the test conditions with a high degree of tolerance and dimensional stahility. ESD grades of PAEK are use together with precision injection moulding for fine connector arrays. Blends of PAEK with amorphous polymers, or less crystalline polymers such as PEKK, can offer a lower tendency to warp and higher dimensional tolerance. 

The latest generation of PEKK polymers are high molecular weight made by Friedel-Crafts chemistry. Depending on the isophthalyl and terephthalyl content, PEKKs can be amorphous or semicrystalline [58]. When all the linkages are terephthalyl, PEKK exhibits a of 165 °C and T of 391 °C. The structure... 

Blend patent work describes a process for producing a solution blend of PBI and an amorphous PEKK. The objective was to prepare solution-derived blends of 100-mesh PBI polymer with PEKK, and to evaluate the thermal properties (Figs 7.6 and 7.7 show the TGA curves for PBI and PEKK, respectively). The PBI is mixed with sulfuric acid at a temperature between 40°C and 80°C for 30 min to 2 h to produce a PBI solution, then cooled to... 

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