Properties of Commercial LCPs

Table 19.38 Typical properties of commercial LCP/PPS blend (GF-reinforced)...

A list of tensile properties of various LCP fibers in comparison with those of typical thermoplastic fibers is made in Table 8.4. It should be noted that the fiber properties of TLCPs in Table 8.4 are not for commercial fibers and should be used only for a comparison purpose. The fiber spinning, orientation, and properties of TLCP fibers have been well reviewed in the literature [121,122],... 

Properties of Typical Commercial LCPs. Table 17 presents data on three significant, commercially available LCPs (238). Elongation values have been quoted for HX-2000 as 0.6%, for Xydar G-930 as 1.6%, and for Xydar G-540 as 1.5%. Eurther details can be obtained from the manufacturers. 

In many commercial LCP s, annealing at conditions 10 -30 C below the melting point produces remarkable increases in mechanical properties. Along with the increased ordering of the molecular structure, many polymers exhibit a dramatic rise in intrinsic viscosity, suggesting that solid-state polymerization is occurring. 

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... 

Some commercial available LCPs, including Xydar and Zenite have been extensively characterized by infrared spectroscopy, differential scanning calorimetry, polarized light microscopy, thermogravimetry, and elemental analysis. Some selected properties of a neat LCP are shown in Table 16.2. 

SINCE the discovery of liquid crystalline phenomenon for low molecular weight liquid crystals (LMWLCs) more than 100 years ago, anisotropic ordering behaviors of liquid crystals (LCs) have been of considerable interest to academe [1-8], In the 1950s, Hory postulated the lattice model for various problems in LC systems and theoretically predicted the liquid crystallinity for certain polymers [1-3], As predicted by the Hory theory, DuPont scientists synthesized lyotropic LCPs made of rigid wholly aromatic polyamide. Later, Amoco, Eastman-Kodak, and Celanese commercialized a series of thermotropic main-chain LCPs [2]. Thermotropic LCPs have a unique combination of properties from both liquid crystalline and conventional thermoplastic states, such as melt processibility, high mechanical properties, low moisture take-up, and excellent thermal and chemical resistance. Aromatic main-chain LCPs are the most important class of thermotropic LCPs developed for structural applications [2,4-7]. Because they have wide applications in high value-added electronics and composites, both academia and industry have carried out comprehensive research and development. 

Ternary blends containing LCPs also show an attractive approach to the development of reinforced systems. The differences between ternary polyblends and polyblends with a third component (a compatibilizer) added are that in the latter, usually the third components is a pre-made compound (or polymer) and its fraction in compatibilized blends is less than 10 wt%. The third polymer used in ternary blends is an as-received commercial product, and its content in ternary blends can be changed for tailoring the properties of blends. 

Typical LCP mbe properties are shown in Table 11.3. The LCP tube properties of Table 11.3 are for isotropic, biaxially oriented tube, processed as described below. Table 11.4 shows me trade names and temperature capabilities for me commercially available LCPs. 

Figure 11.18 shows commercial LCP tube made by Superex Polymer, Inc., from Vectra B-130, Zenite 6130, andXydar G-930 resins. Table 11.6 shows properties of the tubes. 

Mechanical properties. SIVERAS has the highest level of mechanical properties among all the commercial LCPs in particular, it has the highest weld strength, which is the most desired property of LCP materials. 

Interest, academic and Industrial, In Liquid Crystal Polymers (LCP s) was sparked by the commercialization of Kevlar aromatic polyamide fiber In the early 1970 s. [1,2] This fiber can be made almost as stiff and as strong as steel, at one fifth of the density of steel. In addition. It has good resistance to chemical attack and outstanding resistance to heat. From a scientific point of view, LCP s are Interesting because they. In addition to displaying a variety of phenomena and properties seen with conventional Isotropic polymers, also exhibit many of the complex physical properties of small molecule liquid crystals.[3]... 

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