Abstract: A process for preparing a three-branched or four-branched star compound comprising polymerizing an olefine compound represetned by the formula ##STR1## wherein A is a signle bond or phenylene group, and R.sup.3 is a hydrogen atom or methyl group and R.sup.4 is a monovalent organic group when A is a signle bond, or R.sup.3 is a hydrogen atom and R.sup.4 is an alkyl group when A is a phenylene group, using the adduct of a polyfunctional alkenyl ether represetned by the formula (I)R.sup.2 --O--CH.dbd.CHR.sup.1).sub.n (I)wherein R.sup.1 is a hydrogen atom or methyl group, n is an integer of 3 or 4, and R.sup.2 is a rtivalent organic group when n is 3 or a tetravelent organic group when n is 4 with a cation-donating compound.

Abstract: A permselective membrane having an improved gas-permeability and selectivity is obtained from a polymer of 1-alkyldimethylsilyl-1-propyne.

Abstract: A permselective membrane having improved gas-permeability and selectivity is obtained from a polymer of 1-alkyldimethylsilyl-1-propyne.

Abstract: A process for preparing reactive polymers and polymers prepared by the foregoing process are disclosed. This process comprises polymerizing a monomer comprising at least one isopropenylphenyl glycidyl ether represented by formula (1): ##STR1## wherein all the symbols are defined in the appended claims, or in combination with at least one other unsaturated monomer, by the use of a catalyst selected from halogens and hydrogen iodide. The reactive polymer prepared by the above process is represented by the general formula (2): ##STR2## wherein all the symbols are defined in the appended claims, and has a number average molecular weight of 500 to 50,000.

Abstract: Provided is a membrane for liquid separation which comprises mainly poly(substituted acetylene) having a repeating unit represented by the following formula: ##STR1## wherein R.sub.1 represents a hydrogen atom or a methyl group, and R.sub.2 represents an alkyl group having from 1 to 3 carbon atoms.