Abstract: Process for anionically polymerizing a conjugated 1,3-diene monomer consists of contacting the monomer in an inert hydrocarbon solvent with a monofunctional silyl ether initiator of general formula R.sup.1 R.sup.2 R.sup.3 Si--O--A--Li where R.sup.1 to R.sup.3 are independently selected from monovalent organic substituent groups and A is a short chain hydrocarbon bridging group, to yield a polydiene having a molecular weight of typically 1,000-10,000, a high 1.4 content of typically 90% and a low polydispensity of typically 1.15. The reactive ends of the living polymer chains may be terminated with a reactive group such as hydroxyl by treating the polymer with ethylene oxide. Subsequent removal of the polymer's relatively unreactive silyl end groups by reaction with tetra-n-butylammonium fluoride produces a difunctional, chain-extendable, hydroxy-terminated polydiene useful as a rubbery binder prepolymer.

Abstract: Process for anionically polymerising a conjugated 1,3-diene monomer consists of contacting the monomer in an inert hydrocarbon solvent with a monofunctional silyl ether initiator of general formula R.sup.1 R.sup.2 R.sup.3 Si--O--A--Li where R.sup.1 to R.sup.3 are independently selected from monovalent organic substituent groups and A is a short chain hydrocarbon bridging group, to yield a polydiene having a molecular weight of typically 1,000-10,000, a high 1.4 content of typically 90% and a low polydispensity of typically 1.15. The reactive ends of the living polymer chains may be terminated with a reactive group such as hydroxyl by treating the polymer with ethylene oxide. Subsequent removal of the polymer's relatively unreactive silyl end groups by reaction with tetra-n-butylammonium fluoride produces a difunctional, chain-extendable, hydroxy-terminated polydiene useful as a rubbery binder prepolymer.

Abstract: This invention relates to the production of hydroxy-terminated polymers in the 2,000-20,000 MW range suitable for use as prepolymers in curing reactions with isocyanates to produce elastomers. The process involves the continuous addition over periods of 25-50 hours of an oxirane (monoepoxide) or a mixture of an oxirane and an oxetane to a reaction mixture, consisting of stoichiometric excesses of oxonium ion-forming catalyst such as BF.sub.3 -etherate and a diol initiator dissolved in an inert solvent. Under these conditions, chain extension of the diol occurs and the formation of cyclic oligomers and other impurities is minimised. The mole ratio of the initiator to catalyst is maintained at above 10:1 to suppress the formation of cationic terminal species on the growing polymer chain.

Abstract: Hydroxyterminated prepolymers, used in curing reactions with isocyanates to produce elastomers, are prepared by continuously adding over periods of 12-50 hours an oxetane monomer to a reaction mixture containing a diol initiator and a catalyst capable of catalyzing the cationic quasi-living cationic polymerization of the monomer, the rate of addition to maintain stoichiometric excess over the monomer. Polymerization is terminated by adding brine. Polymers of increased molecular weight and reduced impurity levels result.

Abstract: The laser imaging material comprises a laser-transparent support layer of, for example, polyester. A first overlying layer is laser-transparent and formed from a binder that is instantaneously thermally-chemically-decomposable with the production of a gas, for example, an acrylic or methacrylic homopolymer or copolymer, a cellulosic polymer, or a homopolymer or copolymer of stryene. A second overlying layer is formed from such a material, the same as or different from that of the first overlying layer, pigmented with carbon black. Upon laser irradiation through the support layer 10, selected portions of the carbon black are transferred to a suitable receptor surface such as paper or a lithographic plate.

Abstract: A process for the anionic polymerization of a conjugated 1,3-diene in a polar solvent consists of contacting the 1,3-diene with an organo alkali or alkaline earth metal initiator and a sterically hindered Lewis acid, allowing the 1,3-diene to polymerize in the polar solvent and terminating the polymerization reaction. Preferably the Lewis acid is a substituted triaryl derivative of a Group III element, especially boron. However in certain cases (e.g. where the aryl derivative itself is large) the Lewis acid may be an unsubstituted triaryl derivative of a Group III element. Suitable Lewis acids include trimesityl boron and tri (2,6-dimethylphenyl) boron. In preferred embodiments of the present process the 1,3-diene is butadiene, the polar solvent is tetrahydrofuran and the initiator is a difunctional initiator, especially an electron transfer reagent.