摘要:
A process for preparing a modified, amorphous poly-(2,6-dimethyl-p-oxyphenylene) (PPO) comprises:(a) metalating PPO with a metalating agent, and(b) functionalizing such a metalated PPO by reacting the PPO with a trialkylsilyl halide and/or ethylene oxide; and is characterized in that the reaction of metalation is carried out in an inert liquid vehicle which contains PPO in an at least partially suspended solid form, by operating under metalating conditions of gradually adding metalating agent to such a suspension, either continuously or as discrete portions. Depending on the functionalizing agents used, and on the sequence of addition thereof, the process makes it possible to obtain PPO polymers which are modified with trialkyl-silyl, hydroxyethylene and/or ethyleneoxytrialkyl-silyl functional groups. The modified PPO polymers are particularly suitable for preparing flat membranes, including asymmetrical membranes, for the separation of gas mixtures.
摘要:
Graft-polymers of,.alpha.,.alpha.'-disubstituted .beta.-propiolactones on isobutylene-triene copolymers are prepared by reacting an isobutylene-triene copolymer with maleic anhydride and possibly with other functionalizing agents adapted to introduce acid and ester groups in the copolymer molecule and by neutralizing or hydrolyzing, or both, with a tetraalkylammonium base, said functional groups, said neutralization or hydrolysis, or both, being followed by a grafting reaction with pivalolactone.
摘要:
A solid polymeric electrolytic membrane comprising a solution of an ion compound in a cross-linked polyether including a liquid plasticizer obtained by:a) copolymerizing a vinyl ether of the formula:R--(O--CH.sub.2 --CH.sub.2 --).sub.n --O--CH=CH.sub.2 (I)with an allyl vinyl ether of the formula:CH.sub.2 =CH--CH.sub.2 --(O--CH.sub.2 --CH.sub.2 --).sub.m --O--CH=CH.sub.2 (II)where R is a methyl or ethyl radical, n is an integer ranging from 1 to 16, m is an integer ranging from 1 to 10 and the molar ratio of (I) to (II) is between 70/30 and 95/5, forming an allyl copolymer; b) hydrosilating the allyl double bonds of the allyl copolymer by reaction with trimethoxy or triethoxy silane to form a hydrosilated copolymer; c) cross-linking the hydrosilated copolymer by means of a diprotic cross-linking agent in a plasticizer solution of an oligomer or a dipolar aprotic solvent present in a quantity of 20 to 80% by weight and in the presence of an ion compound, and evaporating the low-boiling compounds formed in step c) to obtain a membrane capable of retaining the liquid plasticizer.
摘要:
Compounds of general formula ##STR1## wherein: R is a linear or branched C.sub.1 -C.sub.20 alkyl radical, m is either 0 or 1; n has a value of from 1 to 10, are corrosion inhibitors, suitable for inhibiting the general corrosion and the stress brittlening caused by hydrogen sulfide (SSC), in an acidic environment, in the presence, or absence of carbon dioxide, of medium-and high-strength manganese steels and low-alloy steels, commonly used in petrochemical facilities and in bore drilling, transport and processing systems for natural gas or petroleum.
摘要:
An amorphous modified poly(2,6-dimethyl-p-oxyphenylene) (PPO) is described with a glass transition temperature (Tg) within the range of 170.degree.-220.degree. C., of which the macromolecules contain units having trialkylsilyl groups bonded to the nucleus and/or to the methyl: ##STR1## together with units having hydroxyethyl groups bonded to the nucleus and/or to the methyl: ##STR2## This modified PPO is prepared by metalating PPO with a metalating agent and reacting the formed metalated PPO with a trialkylsilyl halide and with ehtylene oxide in succession.The use of the thus modified PPO for the preparation of flat, including asymmetric, membranes useful in gas mixture separation processes is described.
摘要:
Coupling agents of general formula ##STR1## and their use in a method for the termination of living polymers obtained by the anionic polymerization of dienic and/or vinylaromatic monomers.
摘要:
Coupling agents of general formula ##STR1## and their use in a method for the termination of living polymers obtained by the anionic polymerization of dienic and/or vinylaromatic monomers.
摘要:
Coupling agents of general formula ##STR1## and their use in a method for the termination of living polymers obtained by the anionic polymerization of dienic and/or vinylaromatic monomers.
摘要:
Coupling agents of general formula ##STR1## and their use in a method for the termination of living polymers obtained by the anionic polymerization of dienic and/or vinylaromatic monomers.
摘要:
Multifunctional anionic initiators having the general formula: ##STR1## and process for synthesizing said initiators and their use in polymerizing dienic monomers and for making block polymers.