LCP/Celanese

Celanese Vectra A130 30% glass fiber-reinforced, standard-grade LCP Celanese Vectra A230 30% carbon fiber-reinforced, high-stiffness LCP... 

Four companies (trade name in parentheses), Amoco (Xydar), Hoechst-Celanese (Vectra), Du Pont, and Granmont (Granlar), make thermotropic LCPs for various types of extmsion and mol ding processes. Six companies have discontinued TCP materials that were either commercial or under development. These companies include ICl, BASF, Eastman, Bayer, General Electric, and Monsanto. 

Vectra Fliissigkristalline Polymere (LCP), brochure from Hoechst Celanese, September 1989/1. Auflage. 

Compared with other polymeric materials. LCPs have very high unidirectional properties. Iei/nt7 1 (Celanese Corp.t resins are primarily aromatic polyesters based on p-hydroxybenzoic acid and hydroxynaphthoic acid monomers. Xytlar " (Celanese Carp.) injection molding resins are polyesters based on terephthalic acid. />. p -dihydruxybiphenyl and p-hydroxybenzoic acid Differences in monomers are primarily responsible for the differences in specific properties and end uses. The fibrous nature of the polymers imparls good impact strengths. 

A whole series of high-performance polyester LCPs was introduced in 1985. They were assembled from p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid. Polyarylates (PARs) - amorphous phenolic esters derived from aromatic dicarboxylic acids (mixtures of terephthalic acid and isophthalic acid) and biphenols such as bisphenol A - are produced by Amoco (Ardel ), Celanese (Durel ) and DuPont (Arylon ) at a volume of approx. 2000 t/a. 

To date, reports of investigations on the gas transport properties of main chain liquid crystalline polymers appear to have been limited to the work conducted in our laboratory. Chiou and Paul (4.) have briefly described the transport parameters of an extruded film of an LCP having a similar structure to the commercial product Vectra. This copolyester belongs to the family of napthylene thermotropic polymers (NTP s) commercialized by Hoechst-Celanese Corp. whose synthesis and properties have been described previously (iLS.). Transient permeation experiments were conducted with a series of gases. The effective... 

The LCP system Vectra B950 (an aromatic copolyesteramide) from Hoechst-Celanese was intended to be used as such a reinforcing fibre phase in a polypropylene (PP) matrix. We were requested to determine the thermal transition effects of Vectra B950 in order to use these effects to determine small amounts of Vectra B950 in a PP matrix by DSC. 

Recently a PPS blend with liquid crystalline polyesters (LCP) has also been offered commercially in 40% glass tilled form (Vectra V140, Hoechst-Celanese). The liquid crystalline polyester used in this blend is a copolyester of p-hydroxybenzoic acid and 2-hydroxy-6-naph-thoic acid. The melting point of this LCP and of PPS closely match, i.e., T = 285 to 290°C. Since there is no compatibility or reaction between the two components, LCP/PPS blend is considered to be a simple mechanical blend. 

Table 15.34. Typical properties of LCP/PPS blend (Vectra V140, Hoechst-Celanese) (40 wt% glass liber reinforced)...

A second range of LCPs were introduced by Hoechst Celanese under the trade name Vectra. Vectra is an aromatic polyester condensate derived from 2,6-dihydroxynaphthalene. Its main advantages are its fast cycling and ease of processing, the melt temperature for both injection and extrusion grades being typically about 285°C. 

Vectra Celanese LCP blends — High-T mechanical properties... 

In particular, the results of the poly (HNA/p-HBA) series are the basis for the commercial development of a family of thermotropic LCPs by the Hoechst Celanese Cor-... 

Hoechst Celanese also officially introduced Vectra in the US at the same time, thus 1985 can be recognized as the first year of LCP worldwide. 

As an example, the structure of Celanese Vectra A950 LCP is shown in Figure 4.107. 

Figure 4.110 Stress vs. strain at various temperatures for Celanese Vectra A530—30% mineral reinforced, standard grade LCP.

Figure 4.114 Stress vs. strain at 23°C for several Celanese Vectra L130—30% glass fiber reinforced, high flow LCPs.

Figure 4.116 Influence of temperature on tensile stress-strain behavior of Celanese Vectra B230 LCP [9].

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