Anionic polymerization history

The development of high styrene content styrene-butadiene copolymers (SBCs), such as K-Resin SBC, is best thought of as a branch off the history of anionic polymerization and rubber. A number of excellent reviews cover this aspect of the subject in great detail, and should be obtained for detailed examination of the history of rubber and anionically synthesized rubber polymers [1-3]. What follows is a brief overview to fit the high styrene content SBC into a historical context. 

The outlier in this group is VC, which contains a double bond capable of polymerization by either a radical or anionic mechanism on the anode. This stmcture provides another mechanism of surface film formation besides the formation of insoluble lithium carbonates and lithium alkyl carbonates. Although the study on VC as an additive has more than 20 years of history, its working mechanism in batteries is stiU under debate. While some chemists believe VC is involved with radical/anionic polymerization, as there has been experimental proof of such a product [36], other chemists have proposed mechanisms that involve the interaction of VC with reduction products of EC, which agrees with the observation of gas products such as CO and CO2 (Scheme 1) [126, 135]. Electrochemical processes can be very complicated, and in batteries they can be even more convoluted due to the heterogeneous surface chenustiy of electrode materials. There is experimental evidence to support both of these mechanisms. Even though the success of VC is... 

Ever since Petersen reported the complexing ability of the crown ether with alkali, alkaline earth and other cations, crown ether became a major subject for researchers. This is due to the fact that crown ether possesses the ability to form complexes with a variety of inorganic salts and also the ability to solubilize these salts in aprotic solvents The complexation between metal cation and crown ether is believed to involve ion-dipole interactions and therefore is similar in nature to ordinary solvation. In addition, crown ether/metal cation complexes can serve as catalysts in reactions involving ionic intermediates. Polymerization of diene with crown ether/metal cation complexes is a typical example of this subject, since this reaction involves ionic intermediates. The detailed information including a brief history, chemical properties of crown ether and its application in the anionic polymerization and copolymerization have been discussed. 

The history of well-defined BCPs with polyphenylene segments is quite long, similar to polyacetylenes (Section 13.3.1). In 1988, Francois et al. synthesized poly(p-phenylene)(PPP)-b-PS rod-coil BCPs based on living anionic polymerization (Zhong and Francois, 1988). After the sequential polymerization of styrene and cyclohexadiene, the poly(cyclohexa-l,3-diene)-b-PS was synthesized and subsequently aromatized with p-chloranil to afford the desired PPP-b-PS. Although the aromatization was not complete, they discovered special nonequilibrium honeycomb structures in which monodisperse pores are arranged in a hexagonal array by... 

Polylactides, 18 Poly lactones, 18, 43 Poly(L-lactic acid) (PLLA), 22, 41, 42 preparation of, 99-100 Polymer age, 1 Polymer architecture, 6-9 Polymer chains, nonmesogenic units in, 52 Polymer Chemistry (Stevens), 5 Polymeric chiral catalysts, 473-474 Polymeric materials, history of, 1-2 Polymeric MDI (PMDI), 201, 210, 238 Polymerizations. See also Copolymerization Depolymerization Polyesterification Polymers Prepolymerization Repolymerization Ring-opening polymerization Solid-state polymerization Solution polymerization Solvent-free polymerization Step-grown polymerization processes Vapor-phase deposition polymerization acid chloride, 155-157 ADMET, 4, 10, 431-461 anionic, 149, 174, 177-178 batch, 167 bulk, 166, 331 chain-growth, 4 continuous, 167, 548 coupling, 467 Friedel-Crafts, 332-334 Hoechst, 548 hydrolytic, 150-153 influence of water content on, 151-152, 154... 

Early laser Raman spectroscopic studies concluded that dilute, 0.3 M sodium siHcate solutions of varying ratios (m = 0.33-3.3) contain an equiHbrium mixture of monomeric siHcate, SiO(OH) 2 and Si02(0H) 2> polymeric anions, regardless of their histories and methods of preparation. Subsequent... 

The history and early developments in the pioneering work of polymers up to the most recent advancements are covered. Olefin polymerization started about 100 years back without involvement of metals, following anionic or radical pathways. The contemporary olefin polymerization industry depends mainly on the use of metal complexes as catalysts. At the present time, metal-catalyzed polymerization represents the most successful, conceivable, and sustainable procedure toward the synthesis of polyolefins. Nowadays, the list of metals includes several transition metals in the generation of catalysts. In doing their catalytic role, they foUow various mechanisms that lead to a wide range of polymeric products. 

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