摘要:
A method for the detection and quantification, in a complex aqueous fluid, of additives and water-soluble polymers used in the enhanced recovery of oil and shale gas.
摘要:
A new type of poly-2-pyrrolidone suitable for melt spinning and a process for its preparation. The new poly-2-pyrrolidone is characterized in that the polymer in the virgin state has a relative viscosity (1 gram of polymer in 100 ml of 96% sulphuric acid at 20.degree. C.) of between 2.2 and 7.0, shows a weight loss of less than 5% by weight when heated from 20.degree. C. to the onset temperature of thermal degradation at a rate 4.degree. C. per minute, the ratio between the relative viscosities after and before melt spinning ranges between 0.50:1 and 0.95:1, and the relative viscosity after melt spinning is at least 1.90. The new poly-2-pyrrolidone is prepared by polymerization of 2-pyrrolidone in the presence of an anionic catalyst and an accelerator wherein N-(2-caprolactim)-caprolactam is used as the accelerator in an amount of between 0.05 and 5.0 mole percent relative to the monomer, and the polymerization is carried out at a temperature of between about 25.degree. and 70.degree. C. until a relative viscosity of at least 2.2 is obtained.
摘要:
The polymerization of 2-pyrrolidone is achieved in high yield in the presence of a sodium-derived catalyst activator produced by the reaction of carbon dioxide with the sodium lactamate derived from the reaction of a sodium alkoxide and a 5-7 membered-ring lactam in an inert liquid nonsolvent.
摘要:
There is disclosed a method of forming pure white polymers of 2-pyrrolidone when using SO.sub.2 as the activator. The method involves the use of the rubidium or cesium salt of 2-pyrrolidone as the alkaline catalyst in place of the sodium or potassium salt customarily used and which cause the formation of yellow polymer.
摘要:
A method of recovering and recycling quaternary ammonium accelerators for the polymerization of 2-pyrrolidone is disclosed. The method consists of removing the quaternary ammonium compound together with unpolymerized 2-pyrrolidone by washing the polymer with a solvent for both, such as water or methanol, neutralizing the solution immediately after washing and then removing the solvent at a sufficiently low temperature so that the quaternary ammonium compound is not decomposed.
摘要:
Filaments and fibers formed from a ternary fibre-forming polyamide consisting essentially of the polymeric condensation product of (1) at least 50 percent by weight of hexamethylene diammonium adipate, (2) 20-40 percent by weight of hexamethylene diammonium terephthalate and (3) 2-20 percent by weight of a third polyamide.
摘要:
An improved process for the polymerization of 2-pyrrolidone provides high-molecular-weight poly-2-pyrrolidone at higher rates of conversion by effecting the alkaline-catalyzed polymerization in the presence of a synergistic activator consisting of carbon dioxide and sulfur dioxide.
摘要:
The process of making catalyst for the alkaline catalyzed polymerization of 2-pyrrolidone, in which an alkali metal is contacted with a 5-7 membered-ring lactam and the product alkali metal lactamate is obtained by distillation in the residuum containing about 50-95% of the total lactam. The alkali metal lactamate so obtained is used as a catalyst in the polymerization of 2-pyrrolidone, or may be contacted with carbon dioxide to form an adduct which finds use as an activator in the polymerization of 2-pyrrolidone.
摘要:
In the preparation of a catalyst for the alkalinecatalyzed polymerization of pyrrolidone, an alkali metal alkoxide is contacted with excess 2-pyrrolidone and the product alcohol is removed by passing an inert gas through the reaction mixture at high temperatures.
摘要:
In an improved process for making catalyst for the alkaline-catalyzed polymerization of 2-pyrrolidone, potassium metal is contacted with a 5-7 membered-ring lactam and the product, potassium lactamate, is substantially isolated. The potassium lactamate so-derived finds use as a catalyst in the polymerization of 2-pyrrolidone or may be contacted with carbon dioxide to form an isolatable adduct which is used as an activator in the polymerization of 2-pyrrolidone.