Whole aromatic polyester

The fiber is then heat treated under tension or stretching, to perfect the crystallization and orientation of crystals of an extended molecular chain. In this way, a high-strength, high-modulus fiber is obtained. Figure 3 shows the fibril structure of a whole aromatic polyester fiber. The molecular structure is shown in Figure 3. It consists of naphthalic acid, two(2)-methyl-para-quinone and para-benzoic acid. The high orientation of the crystals, especially those of the core, is deduced from the fibrillar structure observed. 

Spun-bonded composites, on the other hand, are mainly produced from poly(ethylene), poly(propylene), and aromatic polyesters. Area-bound products behave more like paper, but point-bound products are more like fleeces (Table 38-6). In these cases, composites from poly(ethylcne) and poly-(propylenc) arc purely thermally welded without the use of adhesives the resulting products span the whole of the area of application between heavy packing papers to fine writing papers. The poly(ethylene) papers can be... 

Historically, PET was probably the first polymer that was considered as a model system for the whole group of semirigid semicrystalline polymers including other aromatic polyesters and polyamides. The semicrystalline structure of this polymer has been extensively studied for more than 50 years employing various experimental techniques such as SAXS/WAXS, electron diffraction, TEM, " smaU-angle light scattering,... 

The history of thermoplastic polyester goes back to 1929 with the pioneering work of Carothers. The first aromatic polyester of importance is poly(ethylene terephthalate) commonly abbreviated PET (or PETE) and was prepared by Whinfield and Dickson. In 1941, they created the first polyester fibers called Terylene and first manufactured by Imperial Chemical Industries (ICI). PET was produced commercially in 1953 as fiber for textile industry (Dacron) by Dupont using modified nylon technology. Dupont polyester research rapidly leads to a whole range of trademarked products as Mylar, a strong polyester film. 

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. 

The increased interest in thermotropic wholly aromatic LC polyesters is related above all to their commercial applications. Their ability to exist as anisotropic melts, combined with high molding and extrusion characteristics, allows very easy processing of these materials into various pats and articles. The fundamental aspect of this interest is associated with the fact that, with these polymers, it is possible to examine the effect of chain stiffness and of the influence of regular chain structure on evolution of macromolecular order in polymers on the whole. 

The Biocosafe brand, from Zhejiang Hangzhou Xinfu Pharmaceutical Co. Ltd, is a family of biodegradable polyesters both aliphatic (based on succinic acid - Section 10.2.2) and aliphatic-aromatic. Biocosafe 2003F is based on a copolyester composed of terephthalic acid, adipic acid and 1,4-butanediol. The content of terephthalic acid in the polymer is approximately 42-45 mol% (with regard to the whole dicarboxylic acid content) [42]. 

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