摘要:
A liquid-crystalline polymer having the repeating units represented by the following general formula (II): ##STR1## wherein R.sup.1 is ##STR2## wherein a is an integer having a value of 1 to 10,b is an integer having a value of 0 or 1,c is an integer having a value of 1 to 30,X.sup.1 is --COO--, --O-- or a single bond,M.sup.1 is ##STR3## d is an integer having a value of 1 to 5. The liquid-crystalline polymer exhibits ferroelectricity in a wide temperature range including room temperature and has a high speed of response to electric field.
摘要:
The present invention relates to a process for removing a basic catalyst from a polyether polyol having a hydroxyl number of from 4 to 250 comprising adding from 0.7 to 7 percent by weight of water, based on the polyether polyol, to an alkaline reaction medium containing the polyether polyol at a temperature of from 20.degree. to 120.degree. C.; introducing 1 to 2 times the stoichiometric amount of gaseous carbon dioxide at a temperature of from 75.degree. to 120.degree. C., thereby forming a carbonate salt; and removing the carbonate salt by filtration.
摘要:
The present invention relates to a process for removing double metal cyanide complex catalyst residue(s) from polyol(s) which comprises after polyol formation the steps of: (a) contacting the catalyst residue-containing polyol with an effective amount of an oxidant to cause said residue(s) to form insoluble residues that are insoluble in the polyol, and (b) separating the insoluble residues from the polyol. In another aspect, the present invention relates to the oxidant-free polyol produced by the above process.
摘要:
The present invention relates to copolyethers comprising copolymers of 7,oxa-bicyclo(2,2,1)heptane, and its alkyl-derivatives, with one or more single-ring or condensed-rings cycloaliphatic ethers, comprising the characteristic group; ##STR1## wherein R' is hydrogen and R" is H, a halogen, or an alkyl radical containing a small number of carbon atoms, and which may also be halogen-substituted.If the ether contains one ring only, it contains from 5 to 12 atoms in the ring, and if it contains a condensed-ring system, it contains a total number of from 10 to 18 atoms in the rings.Those copolyethers show a anisotropic behaviour in the molten state, and therefore have liquid-crystal properties.
摘要:
An aryl-ether and/or thioether polymer contains aromatic rings linked to neighboring units Ph X Ph (when Ph is paraphenylene and X is SO.sub.2 and/or CO) through O and/or S and/or a direct link, at least some of said aromatic rings carrying a nuclear suphonamide group having N-aliphatic substitution, preferably with a cationic amino or quaternary ammonium group.A process for making aromatic polymer sulphonyl halides and, thus also sulphonamides, of very low sulphonic acid content, is characterized by working up in substantially anhydrous conditions the mixture resulting from the reaction of an inorganic halide with the corresponding sulphonic acid or salt thereof. The polymer sulphonamides are suitable for separation technologies, especially purification of water by reverse osmosis.
摘要:
Acetal polymer and copolymer are prepared by polymerizing formaldehyde or its cyclic oligomer as a principal monomer, or copolymerizing the principal monomer with a comonomer copolymerizable therewith, using an isopoly acid or an acid salt thereof as a polymerization catalyst.
摘要:
In a first stage, a heterocyclic oxygen compound is polymerized by an ionic route in a vinyl halide and, in a second stage, the vinyl halide, to which other unsaturated monomers capable of being polymerized by a radical route may be added if desired, is polymerized by a radical route in aqueous dispersion and in the presence of the polymerization mixture originating from the first stage.
摘要:
A hydrogel which comprises polymerized moieties derivable from (i) at least one polymerizable cyclic (thio)ether and (ii) at least one hydrophilic homo- or copolymer.
摘要:
A lubricant for use in the processing of plastics is disclosed. The lubricant comprises a polyalkylene oxide made from a monomer selected from the group consisting of aliphatic, non-substituted, 1,2-alkylene oxides containing from about six to about 40 carbon atoms, and mixtures thereof, said polyalkylene oxide having an average molecular weight from about 1,000 to about 6,000. Also disclosed is a process for using such lubricants in the shaping of thermoplastic polymers.
摘要:
An improved process for the production of polytetramethylene ether glycol is disclosed. Polytetramethylene ether glycol is obtained with a high yield by subjecting tetrahydrofuran to ring opening polymerization in the presence or absence of an organic solvent with the use of, as a catalyst, a lithium halide in conjunction with fuming sulfuric acid. Average molecular weight of the glycol product can be controlled in the range of 1000-3000 at will by varying the amounts of the lithium halide and fuming sulfuric acid used.