Polymerization of ethylene sulfide

In the polymerization of cyclic sulfides, cyclization becomes particularly important because of the enhanced basicity (and nucleophilicity) of the linear sulfides in comparison with their parent monomers43). The simplest cyclic oligomer, formed in the polymerization of thiiranes, is a dimer-1,4-dithiane or its derivatives. 1,4-Dithiane was first observed by Bell in the polymerization of ethylene sulfide 441 later Price isolated the styrene sulfide dimer 45) and recently Goethals obtained dimers of isobutylene and cyclohexene sulfides 46 . Structures of these dimers are ... 

Polymerization of Ethylene Sulfide Using Diethyl Zinc-Water Catalyst. 88... 

Polymerization of Ethylene Sulfide Using Acetone-Sodium Catalyst. 89... 

Uses. Magnesium alkyls are used as polymerization catalysts for alpha-alkenes and dienes, such as the polymerization of ethylene (qv), and in combination with aluminum alkyls and the transition-metal haUdes (16—18). Magnesium alkyls have been used in conjunction with other compounds in the polymerization of alkene oxides, alkene sulfides, acrylonitrile (qv), and polar vinyl monomers (19—22). Magnesium alkyls can be used as a Hquid detergents (23). Also, magnesium alkyls have been used as fuel additives and for the suppression of soot in combustion of residual furnace oil (24). 

The cadmium chalcogenide semiconductors (qv) have found numerous appHcations ranging from rectifiers to photoconductive detectors in smoke alarms. Many Cd compounds, eg, sulfide, tungstate, selenide, teUuride, and oxide, are used as phosphors in luminescent screens and scintiUation counters. Glass colored with cadmium sulfoselenides is used as a color filter in spectroscopy and has recently attracted attention as a third-order, nonlinear optical switching material (see Nonlinear optical materials). DiaLkylcadmium compounds are polymerization catalysts for production of poly(vinyl chloride) (PVC), poly(vinyl acetate) (PVA), and poly(methyl methacrylate) (PMMA). Mixed with TiCl, they catalyze the polymerization of ethylene and propylene. 

Tung et al21> have reported on the use of a polymeric thiol transfer agent for use in block copolymer production. Various methods have been used for the anion thiol conversion. Near quantitative yields of thiol arc reported to have been obtained by terminating anionic polymerization with ethylene sulfide and derivatives (Scheme 7.27). Transfer constants for the polymeric thiols are reported to be similar to those of analogous low molecular weight compounds.273... 

By nitric add and sulfuric add. The oxidation of ethylene sulfide with concentrated nitric acid leads to eulfoacetic add, HOaSCHjOOjH. and other condensed acids.8 Sulfuric acid, dilute or concentrated, appears to have only a polymerizing influence.18... 

We begin with the structure of a noble metal catalyst, where the emphasis is placed on the preparation of rhodium on aluminum oxide and the nature of the metal support interaction. Next, we focus on a promoted surface in a review of potassium on noble metals. This section illustrates how single crystal techniques have been applied to investigate to what extent promoters perturb the surface of a catalyst. The third study deals with the sulfidic cobalt-molybdenum catalysts used in hydrotreating reactions. Here, we are concerned with the composition and structure of the catalytically active surface, and how it evolves as a result of the preparation. In the final study we discuss the structure of chromium oxide catalysts in the polymerization of ethylene, along with the polymer product that builds up on the surface of the catalyst. 

Polymerization of ethylene oxide is a suitable example of the intramolecular tomina-tion. R)lyma ization of other thr -ntembwed monomers like ethylene sulfides and N-substituted aziridines also terminates intranwlecularly. This conclusion is based on the studio of the final monoma concentration and its dependence on the starting initiator concentration. 

Polymerizations of ethylene oxide and propylene sulfide were reviewed several times by the authors of the original results, namely the Paris and the Moscow groups (52), (40). One of us with Kazanski reviewed recently the recent Zita, including also polymerization of lactone s... 

CS2 was polymerized with ethylene sulfide or propylene sulfide in the presence of diethyl zinc to give poly(trithiocarbonate) [166]. 

We previously reported the synthesis of thiol-modified silica-polyamine composite using ethylene sulfide. Although the reaction of ethylene sulfide with WP-1 gave a material that had excellent mercury capture characteristics, this ligand is toxic and difficult to make and handle. In addition, ethylene sulfide polymerizes with itself in the presence of nucleophiles therefore, we could not tell if we were dealing with an amino-thiol ligand (Fig. 16 ) or a polysulfide ligand (Fig. 165).27... 

The range of monomers that can be incorporated into block copolymers by the living anionic route includes not only the carbon-carbon double-bond monomers susceptible to anionic polymerization but also certain cyclic monomers, such as ethylene oxide, propylene sulfide, lactams, lactones, and cyclic siloxanes (Chap. 7). Thus one can synthesize block copolymers involving each of the two types of monomers. Some of these combinations require an appropriate adjustment of the propagating center prior to the addition of the cyclic monomer. For example, carbanions from monomers such as styrene or methyl methacrylate are not sufficiently nucleophilic to polymerize lactones. The block copolymer with a lactone can be synthesized if one adds a small amount of ethylene oxide to the living polystyryl system to convert propagating centers to alkoxide ions prior to adding the lactone monomer. 

These ligands form extremely stable cation inclusion complexes, called cryptates, In which the cation Is completely surrounded by the ligand and hidden Inside the molecular cavity, and this leads to a considerable Increase of the interionic distance In the ion pairs. It has been shown that such ligands have a marked activating effect on anionic polymerizations (4,5,6). Moreover, the aggregates are destroyed and simple kinetic results have been obtained In the case of propylene sulfide (7,8,9). ethylene oxide (9,10,11) and cycloelloxanes (12) polymerizations. Though the... 

In conclusion, it has been shown that use of cryptates for the anionic polymerization of heterocyclic monomers leatis to a tremendous increase of the rates of polymerization. There are two main causes to the higher reaction rates observed with cryptates. The first one is a suppression of the association between ion pairs in the non polar media, and the second one is the possibility of ion pairs dissociation into free ions in ethereal solvents like THP or THF. By this way, it has been possible to make detailed studies of the propagation reaction for propylene sulfide, ethylene oxide, and cycloslloxanes. 

The polymerization tendencies of episulfideg are also encountered under acidic reaction conditions. Dilute hydrochloric acid, for example, instantly polymerizes ethylene sulfide to an amorphous powder. Under the same conditions ethylene oxide gives 2-chioroothanol in good yield. Hus may he attributed to tho greater tendency of sulfur as compared with oxygen to form onium ions. A comparison of the two reactions may he pictured as shown in Eqe. f3i>) and (40 . 

The reaction of a,co-dilithiumpolyisoprene with ethylene sulfide crosses over very rapidly (4-5 min) at -40 °C in a 50/50 hydrocarbon/tetrahydrofuran mixture, while the subsequent polymerization requires several days 339 These results suggest that it might be possible to prepare ethane thiol terminated polymers under certain conditions. 

Referring to the cationic polymerization of spiro tetrathioorthocarbonates, a five-membered spiro compound, l,4,6,9-tetrathiaspiro[4.4)nonane (129) quantitatively gave polyethylene sulfide) with the complete extrusion of ethylene tri-thiocarbonate as found in the corresponding oxygen counterpart. [103] A six-membered spiro compound, l,5,7,ll-tetrathiaspiro[5.5]undeeane (130), did not... 

The Step 2 product was dissolved in THF and treated with one equivalent of 0.5 M sodium methoxide in methanol at ambient temperature. The mixture was then treated with between 25 and 50 equivalents of propylene sulfide and polymerized for 30 minutes. It was further treated with approximately 10 equivalents of poly (ethylene glycol) monoacrylate as the end-capping agent. The reaction mixture was stirred overnight at ambient temperature and isolated by precipitation in methanol. 

Sulfur analogs of spiroorthocarbonates, namely spirotetrathiocarbo-nates, also undergo cationic polymerization [212]. A 5-membered monomer gives the mixture of polyethylene sulfide) and ethylene trithiocar-bonate ... 

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