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Xiuzhen Wang

Jun Wang

Wen Zhou

Haishan Bu

Zexian Song

The present invention provides a class of thermotropic liquid crystalline polyesters (TLCPs) and molding compositions comprising the polyesters and glass fiber. The TLCPs consist essentially of repeat units derived from p-hydroxybenzoic acid (HBA), 6-hydroxy-2-naphthoic acid (HNA), terephthalic acid (TA), and hydroquinone (HQ), and the mole percent of HBA, HNA, TA and HQ is 34-72%, 12-26%, 4-21% and 4-21%, respectively. The TLCPs have a melting temperature equal to or below 355&#xb0; C., an inherent viscosity of 4.0-10.0 dL/g and a Heat Deflection Temperature (HDT) in the range of 260-285&#xb0; C. when compounded with 30% by weight glass fiber. The optimum compositions, selected from the above-mentioned compositional ranges exhibit a relatively low melting temperature and a relatively high HDT. Specified compositions, selected from the above-mentioned compositional ranges have low melting point, which are useful to blend with conventional polymers such as poly (ethylene terephthalate) and nylon etc.

Liquid crystalline polyester compositions

A method of extracting Te and bismuth oxide and recovering byproduct comprises: leaching raw materials with a Te content of &#x2267;1.8% by utilizing a leaching system containing HSO, Cl, Br, NHand NaClO, reducing leach solution with SOgas by precipitation method after separating impurities from it, washing with concentrated hydrochloric acid to obtain tellurium precipitation (18), purifying to obtain Te with a purity of higher than 99.99%. The filtrate produced is used for extracting BiOwith a purity of higher than 99.99% when Bi content in the raw material is &#x2267;2%. Acidic waste solution produced during the process could be returned to the leaching step for recycle.

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Shanghai, China

Xiuzhen Wang