摘要:
The present invention is directed to a process for producing a high molecular weight condensation polymer by removing unwanted by-product(s) from a polycondensation equilibrium reaction mixture using a centrifugal force device equipped with a vacuum.
摘要:
A method for devolatilization of a thermoplastic polymer containing at least one volatile component which includes the following three steps: heating the thermoplastic polymer so that the thermoplastic polymer is a heated liquid or molten thermoplastic polymer, flowing the heated liquid thermoplastic polymer through a packed bed liquid-gas contactor by centrifugal force, and flowing a stripping gas through the packed bed countercurrent to the flow of the heated liquid thermoplastic polymer so that the volatile component volatilizes into the stripping gas from the heated liquid thermoplastic polymer by gas-liquid contacting in the packed bed; and an apparatus therefor.
摘要:
Polybenzazole polymer dopes are spun into fibers at high speed by passing through a spinneret with proper selection of hole geometry, followed by spin-drawing to a spin-draw ratio of at least 20, washing, taking up and drying. The take up speed is at least about 150 meters per minute, and the fibers are spun in at least 10 km lengths without a break.
摘要:
A solid bed adsorptive process for separating a seed oil into two substantially pure triglyceride fractions. The process involves contacting a seed oil, such as castor oil, preferably as a concentrate, with an adsorbent in a bed, the adsorbent having a particle size greater than about 40 microns, and thereafter contacting the adsorbent with a desorbent material, preferably under minimal flow conditions, to obtain a raffinate output stream containing predominantly a second triglyceride and an extract output stream containing predominantly a first triglyceride. Purified fatty acid triglyceride esters obtainable from castor, vernonia, and lesquerella plant oils provide renewable, non-petroleum-based sources of chemical feedstocks.
摘要:
A process of preparing an olefin oxide, preferably propylene oxide, and an alcohol, such as α-ethylphenyl alcohol, the process involving contacting an olefin, such as propylene, and an organic hydroperoxide, such as ethylbenzene hydroperoxide, in the presence of an epoxidation catalyst, preferably, a homogeneous molybdenum catalyst, in a single reactor system or in a multi-reactor system containing a plurality of sequentially interconnected reactors. Each reactor in the single or multi-reactor system is preferably divided into a plurality of reaction zones designed to facilitate plug flow behavior. The olefin is fed to a first reaction zone in the single reactor system or to a first reactor in the multi-reactor system. The organic hydroperoxide feed is split into a plurality of split organic hydroperoxide feedstreams, and the split feedstreams are distributed throughout the reaction zones, or the reactors, or both.
摘要:
Described herein is a method for producing epoxides which is continuous, inhibits formation of chlorinated byproducts, and eliminates or substantially reduces waste water discharge. The method includes:(a) forming a low chlorides aqueous hypochlorous acid solution;(b) contacting the low chlorides aqueous hypochlorous acid solution with at least one unsaturated organic compound to form an aqueous organic product comprising at least olefin chlorohydrin;(c) contacting at least the olefin chlorohydrin with an aqueous alkali metal hydroxide to form an aqueous salt solution product containing at least epoxide; and(d) isolating the epoxide from the aqueous salt solution;wherein water is recovered from the product of at least Step (b) and recycled into Step (a) for use in forming the low chlorides aqueous hypochlorous acid solution. In this process, not only is the water internally recycled after Step (b), but a concentrated brine solution is generated in both Steps (a) and (d) which is useful in other processes such as electrochemical production of chlorine and caustic. The chlorine and caustic, in turn, may then be recycled back to the method of this invention.
摘要:
Polybenzazole polymer dopes are spun through a spinneret having more than 2 per cm.sup.2, of orifices in relatively close proximity. The dope filaments formed, then pass through an air gap which has a temperature of 50.degree. to 100.degree. C. and a gas flow sufficient to uniformly reduce the temperature of the dope filaments. The filaments cool in the air gap and are then coagulated.