Ekkcel

A number of related copolymers were also introduced. Ekkcel C-1000 contained the units (I), (II) and (III) whilst Ekkcel 1-2000 contained the units (I), (IV) and (V) Figure 25.22). 

LC materials have also been employed as films, plastics, and resins. Poly(l,4-benzoate) has been marketed under the name Ekonol. It decomposes before it melts, hence it does not form LC melts. Copolymerization with 4,4 -biphenol and terephthalic acid gives Ekkcel,... 

The polymer V containing 67 moles % of p-oxybenzoyl units was marketed by the Carborundum Co. as Ekkcel 12000. According to Jackson 35), the properties of this copolymer, which melts at 380 °C, are highly anisotropic when it is injection-moulded at 400 °C but the melting point proves too high for fibre extrusion. 

The injection molding grade Ekkcel 1-2000 was licensed to Dart Kraft and was sold under the trade name Xydar . However, the melting point... 

There are several commercial TCP s, viz. Ekkcel (degrades at = 400°C), Xydar , Vectra , E-konol , X-7G, Ultrax , KU 1-90, Granlar , Novoaccurate , Rodron , Victrex , etc. TCP s are mainly used for injection molding of parts that require exact dimensions and high performance. 

The tensile strength of this copolymer (EKKCEL 1-2000) is 14,000 psi at room temperature, and 3,000 psi at 500°F. Its heat deflection temperature is 560°F, and the upper use temperature for the polymer will probably be in the range of —575°F. The water absorption is extremely low for this material, as it is for all the aromatic polyesters described here. 

In 1972, Cottis and coworkers at Carborundum patented wholly aromatic polyesters based on p-hydroxybenzoic acid (HBA), A,A -dihydrox-ybiphenyl (DHB), and terephthalic acid (TPA), one of which was later commercialized as EKKCEL 1-2000 [1]. In 1974, Kuhfuss and coworkers at Eastman Kodak reported a new polyester based on HBA and polyfethylene terephthalate) (PET), which was later marketed under the code of X-7G. X-7G is the first thermotropic liquid crystalline polymer to be fabricated by injection molding or melt spinning [2]. However, then Eastman Kodak withdrew its plan of marketing of X-7G and changed the target with a wholly aromatic polyester commercialized as TITAN (THERMX ) in 1996. As described later, it was acquired by DuPont in 2003. 

MELT PRXESSABLE WHOLLY AROMATIC POLYESTER -EKKCEL 1-2000 (CARBORUNDUM)... 

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