Hydrocarbon-Soluble Di- and Multifunctional Organolithium Initiators

Abstract

Soluble difunctional organolithium initiators were prepared by the addition of oligomeric poly(styryllithium) to stoichiometric amounts of double 1,1-diphenylethylene (DDPE) compounds: bis[4-(l-phenylethenyl)phenyl]ether;l,4-bis(l-phenylethenyl)benzene,and4,4,-bis(l-phenylethenyl)-l,r-biphenyl.The resulting products of this addition reaction were soluble in benzene and were capable of initiating diene polymerization. A reversal was detected at the end of the addition reaction to one of the three DDPE compounds, bis[4-(l-phenylethenyl)phenyl] ether. The diphenyl ether group in bis[4-(l-phenylethenyl)phenyl] ether, which might have reacted with poly(styryllithium) to cause a shift of equilibrium, was suspected to be the cause of the anomaly. The styrene-butadiene-styrene triblock copolymer prepared from these difunctional initiators gave narrow and symmetrical chromatograms by GPC. The tensile strength of the block copolymers, however, was low. A potential route of preparing soluble organolithium initiators with functionality higher than 2 was demonstrated.

The Strength of the Macromonomer Strategy for Complex Macromolecular Architecture: Molecular Characterization, Properties and Applications of Polymacromonomers

“…[114][115][116][117][118] He reacted living PS chains with either 1,3-bis(1-phenylethenyl)benzene (MDDPE) or 1,4-bis(1-phenylethenyl)benzene (PDDPE) according to Scheme 25. It was shown, by UV/Visible spectroscopy, that when two moles of the living polymer are added to one mole of PDDPE, the monolithium adduct was formed in polar and nonpolar solvents (Scheme 25).…”

Experimental techniques in high‐vacuum anionic polymerization

“…(1,3-Phenylene)bis(3-methyl-1-phenylpentylidene) Dilithium Initiator (DLI) Synthesis DLI, 21 a difunctional hydrocarbon-soluble organolithium initiator, is synthesized through a twofold adduction of sec-BuLi to a difunctional monomer that cannot itself polymerize. The chemical reaction is given here:…”

Trifunctional organolithium initiator for living anionic polymerization in hydrocarbon solvents in the absence of polar additives

“…5 Attempts to synthesize multifunctional initiators via direct multilithiation, using multifunctional alkyl halides, have been limited due to eliminations caused by lithium-halogen exchange and intermolecular coupling reactions. 9,10 Highly studied difunctional organolithium initiators in non-polar solvents based on double DPE groups have been thoroughly studied by Tung,11,12 Quirk,13,14 Hocker, 15 and Szwarc. 8 However, alkyllithium compounds and their state of aggregation have complicated the synthesis of di-and trifunctional organolithium initiators in non-polar media.…”

“…Polar additives, such as amines, ethers and alkoxides have therefore been mandatory in order to break carbanion-Li aggregates. 12,33 However, the synthesis of an effective hydrocarbon-soluble initiator, particularly a trifunctional initiator not requiring any polar additives, has not been reported in the literature. Introduction of polar additives enhances the solvation of counterion and the insertion of 1,2diene microstructure, which is not desired when polydienes are synthesized in non-polar media.…”