Patent GB-996310-A (GB)
Title: Modified polymeric products
IPC: D06M13/03
Filed: 1962-03-28
Abstract: A film, fibre or fibrous fabric formed from a polymeric mass which (1) has an apparent second order transition temperature of at least 20 DEG  C., (2) is composed of linear polymeric molecules and (3) contains units of at least one polymerized monoethylenically unsaturated aromatic compound and units of at least one polymerized linear aliphatic polyene, is alkylated using hydrogen fluoride as an alkylation catalyst under such conditions that the aromatic nuclei in the polymeric mass are alkylated by polymerized polyene units giving a cross-linked product which is resistant to solvents.  Alkylation of non-aromatic portions of the polymer system may also occur.  The polymeric mass may be a copolymer of one or more linear aliphatic polymers with one or more of the aromatic compounds, preferably containing 50-95% by weight of the latter, or may be a blend of homo-polymers of each class of monomers or a blend of two or more copolymers.  A blend with natural or synthetic rubbers may be used. The proportion of polymerized polyene in the mass is preferably 10-40% by weight. The preferred monoethylenically unsaturated aromatic compounds have the formula CH2=C(R)Z, where R is hydrogen or an alkyl group, advantageously of less than 3 carbon atoms, and Z is an aryl group having an aromatic nucleus susceptible to alkylation. Specified compounds are vinyl aryls such as styrene vinyl naphthalene, vinyl diphenyl and vinyl fluorene and nuclear-substituted derivatives thereof, e.g. alkyl, aryl, alkaryl, aralkyl, cycloalkyl, alkoxy, aryloxy, chlorofluoro, chloromethyl, fluoromethyl and trifluoromethyl derivatives such as o-, m- and p-methyl-styrenes, dimethyl-styrenes, ethyl-styrenes, iso-propyl-styrenes, tolyl-styrenes, benzyl-styrenes, cyclohexyl-styrenes, methoxy-styrenes, phenoxy-styrenes, chlorostrenes, fluorostyrenes, chloro - methyl - styrenes, fluoro-methyl-styrenes, trifluoro-methyl-styrenes, vinyl-methyl naphthalenes, vinyl-ethyl-naphthalenes, vinyl-chloro-naphthalenes and vinyl - methyl - chloro - naphthalenes.  The corresponding a -methyl vinyl, a -ethyl vinyl and a -propyl vinyl compounds may also be used. Specified linear aliphatic polyenes are butadiene-1,3; isoprene; 2,3-dimethyl-butadiene-1,3; 2 - methyl - pentadiene - 1,3; hextriene-1,3,5; myrcene; ocimene; allo-ocimene; chloroprene; fluoroprene and 1-phenyl-butadiene-1,3. The material to be alkylated may be immersed in, sprayed with, or padded with liquid hydrogen fluoride at 20 DEG  C. or less for e.g. 1 to 10 minutes, or in liquid hydrogen fluoride at 80 DEG  C. or more under a pressure of up to 1000 lb./sq. inch, or gaseous hydrogen fluoride may be used at elevated temperature.  The hydrogen fluoride, either gaseous or liquid, may be used in conjunction with boron trifluoride.  The intensity and duration of the treatment is preferably such that the material treated is rendered shrink proof at 90 DEG  C. to 200 DEG C. or more, and is completely insoluble in organic solvents such as toluene.  Termination of the alkylation may be effected by volatilization of the hydrogen fluoride followed by immersion of the material in water, methanol or an alkaline solution.  The treatment is advantageously applied to fibres or films in which the molecules are orientated in at least one extensive direction as by stretching. The alkylation treatment is preferably such that 75% or more of this orientation is retained.  It is not essential to tension the material during treatment.  Such products may have a dry tensile strength of at least 0.5 grams/denier. An example describes the wet spinning of an aqueous dispersion, containing 5% toluene and 40% polymer solids consisting of 85 : 15 styrene and butadiene, into a coagulating bath containing aqueous hydrochloric acid and p-diisobutyl phenoxyethoxy ethyl dimethyl benzyl ammonium chloride at 85 DEG  C.  In a further example, a yarn of filaments of a blend of 85 parts of polystyrene and 15 parts of polybutadiene which has been stretched 500% is immersed in hydrogen fluoride at 15 DEG  C. for 10 minutes, subjected to a stream of air at 30 DEG  C., rinsed in water and dried.  The resultant cross-linked yarn undergoes less than 4% shrinkage at up to 115 DEG  C.  The alkylation treatment may be applied to films, pellides, fibres, tows, yarns or all types of woven and non-woven fabrics. The alkylated products may be used for separation of organic liquids or as ion-exchange media (see Division B1).ALSO:A mixture of miscible organic liquids is separated by selective absorption on a cross-linked polymer prepared from a polymeric mass containing units of monoethylenically unsaturated aromatic compounds, and units of polymerized linear aliphatic polyenes, by treatment with hydrogen fluoride such that alkylation of aromatic nuclei by polyene units occurs (Divisions B5 and C3). The cross-linked polymer may be in the form of a filamentary tow. In examples, a column consisting of a tow of 80/20 polystyrene-polybutadiene is used to separate pyridine from iso-octane by elution with pentane, and ethylene dichloride from isooctane.  Fibres, films and fabrics of the cross-linked polymers may be converted by amination, haloalkylation or sulphonation, into ion-exchange materials.