摘要:
Anionic polymerization of lactams is carried out in an extruder into which at least one lactam, at least one catalyst and at least one activating agent are introduced and wherein the mixture of said substances is polymerized prior to being extruded through an extrusion die. The output rate of the polymerized substance is controlled by transfer means, such as a metering pump, arranged between the outlet of the body of the extruder and the extrusion die.
摘要:
The instant invention relates to a method for purifying lactams wherein the lactam to be purified is contacted in the fused state with inorganic adsorption agents.The said method comprises contacting the lactam to be purified in the fused state with an inorganic adsorbent, then separating the lactam from the adsorbent and regenerating said adsorbent if desired, wherein said adsorbent is impregnated with at least one impregnation compound selected from the group consisting of an acid and the alkali metal salts which are thermally stable and exert no action on the lactam at temperatures lower tha 250.degree.C.
摘要:
The present invention relates to genes which code for glycosyl hydrolases having an HCA score with the iota-carrageenase of Alteromonas fortis which is greater than or equal to 65% over the domain extending between amino acids 164 and 311 of the protein sequence SEQ ID No. 2 of said iota-carrageenase, and to genes which code for glycosyl hydrolases having an HCA score with the kappa-carrageenase of Alteromonas carrageenovora which is greater than or equal to 75% over the domain extending between amino acids 117 and 262 of the protein sequence SEQ ID No. 6 of said kappa-carrageenase.
摘要翻译:本发明涉及编码具有HCA评分的糖基水解酶的基因,其中所述糖基水解酶具有与所述蛋白质序列SEQ ID No.的氨基酸164和311之间延伸的结构域大于或等于65%的阿替单调杆菌的ι-角叉菜胶酶。 2的所述iota-角叉菜胶酶,以及编码具有HCA得分的糖基水解酶的基因,所述糖基水解酶具有与所述蛋白质序列的第117和262位氨基酸之间延伸的结构域大于或等于75%的卡拉胶单胞菌属的卡拉胶 所述κ-角叉菜胶酶的SEQ ID No.6。
摘要:
High molecular weight, essentially uncrosslinked polychlorophosphazenes are prepared by bulk polycondensing a monomer of the formula P.sub.2 NXCl.sub.2, in which X is an oxygen or sulfur atom, e.g., N-dichlorophosphoryl- or N-dichlorothiophosphoryl-P-trichlorophosphazene, and wherein at least that final stage of polycondensation following cessation of evolution of PXCl.sub.3 is carried out in a stirred reaction zone, such stirred reaction zone including means to prevent the accumulation of polycondensate on the stirrer.
摘要:
Crude polyorganophosphazenes, produced by the nucleophilic cosubstitution of polydichlorophosphazenes and contained in a reaction medium which includes such polyorganophosphazenes, reaction solvent for the cosubstitution reaction, excess nucleophilic reagent and/or product of neutralization thereof, and, when present, any alkali metal salts of neutralization, are efficiently and facilely purified, in a single treatment zone, advantageously under agitation in a discontinuous malaxator, by both eliminating the reaction solvent and thereafter washing the resulting reaction medium with a liquid which is a nonsolvent for the polyorganophosphazenes, but miscible with the other products present in said reaction medium.
摘要:
A fire-resistant polycarbonate composition comprising a polycarbonate and for each one thousand parts by weight thereof from about 0.1 to 10 parts by weight of a salt of the formula: ##STR1## in which R is a C.sub.1 to C.sub.6 alkyl radical or an aryl radical, unsubstituted or substituted aryl radical and M is an alkali metal selected from Li, Na, or K.
摘要:
The present invention concerns iodoperoxidases from Zobellia galactanivorans, isolated nucleic acids encoding same, as well as methods for preparing these enzymes. Moreover, the invention is also directed to the use of such iodoperoxidases in a wide range of industrial, pharmaceutical, medical, cosmetics, and ecological applications, as well as in the food industry.
摘要:
The present invention concerns iodoperoxidases from Zobellia galactanivorans, isolated nucleic acids encoding same, as well as methods for preparing these enzymes. Moreover, the invention is also directed to the use of such iodoperoxidases in a wide range of industrial, pharmaceutical, medical, cosmetics, and ecological applications, as well as in the food industry.
摘要:
The sodium fluoroalcoholates are prepared under conditions resulting in neither reactant nor final product degradation, by (a) reacting, under reflux, the corresponding fluoroalcohols, e.g., the mono-, di- or trifluoroethanols, with sodium methanolate in the presence of a solvent having a boiling point higher than that of methanol and/or a solvent which forms an azeotrope with methanol, and (b) selectively trapping the methanol of reaction, e.g., in a molecular sieve, as it is released into the vapors which evolve upon refluxing the step (a) reaction mixture; the sodium fluoroalcoholates thus produced are well suited for direct reaction with polydichlorophosphazenes.
摘要:
A process for preparing linear polychlorophosphazenes having a terminal --PXCl.sub.2 group, wherein X is O or S, by polycondensation of a monomer of the formula P.sub.2 NXCl.sub.5, by heating to release PXCl.sub.3 and continuing the heating after the evolution of PXCl.sub.3 has stopped. In the process, at least the heat induced polycondensation phase after evolution of PXCl.sub.3 has stopped is carried out in solution in a medium which is a solvent for both the monomer and the polymer and which is inert to the constituents of the polycondensation reaction. The process reduces the amount of cross-linking and produces high molecular weight polymers in a reproducible way.