Ethylene sulfide polymerization

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... 

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... 

Colorless liquid that gradually polymerizes. It may be stabilized with 0.5% butylmer-captan. Ethylene sulfide is hazardous through inhalation and ingestion, and produces local skin/eye impacts. 

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 . 

Ethylene sulfide,8 propylene sulfide,88 3-ohloropropylene sulfide,18 and cyclohexene sulfide1 have been converted into 2-chlarothioIs in 33, 60, 72, end 67% yields respectively by reaction with concentrated hydrochloric add. Dilute hydrochloric add, however, leads to more extensive polymerization. 3ft... 

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... 

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. 

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. 

These complexes lead to a considerable increase of the Interlonlc distance In the ion pairs and It has been shown that such ligands have a marked activating effect on anionic polymerizations (14,15, 16). Moreover, the aggregates are destroyed and simple kinetic results have been obtained in the case of propylene sulfide and ethylene oxide polymerizations (12). 

This product can be stored at room temperature for several weeks without polymerization. On distillation, pure ethylene sulfide, b.p. 54.0-54.5°, m 1.4960, is obtained. 

In a practical sense the hydrocarbon monomers that work best in anionic systems are styrene, a-methylstyrene, p-(tert-butyl)styrene, butadiene, isoprene, 2,3-dimethyIbutadiene, piperylene, stilbene, and 1,1-diphenylethylene. The latter two monomers give rise to alternating copolymers with other dienes but do not homopolymerize. Among the polar monomers (C) that can be polymerized are such monomers as 2-vinyIpyridine, pivalolactone, methacrylonitrile, methyl-methacrylate, ethylene oxide (not with Li-counterion), ethylene sulfide, and propylene sulfide. However, polymerization of many of these polar monomers suffers from side reactions and complicating termination or transfer reactions not present in the... 

Aliphatic ethylene sulfides often undergo the same ring-opening reactions as do the oxides, but polymerization usually prevents the isolation of much of the initial product of ring fission. However, good yields of 2-chlorothiols and 2-chlorothiolie acid esters are obtained by reaction with coned. HC1 and acyl chlorides.— E Cyclohexene sulfide — 2-chlorocyclohexyl thiolacetate. (F. e. and reactions s. W. Davies et al., Soc. 1949, 282 1950, 317.)... 

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... 

To a glass flask equipped with a mechanical stirrer, reflux condenser, and thermometer is added 75 ml of acetone and 0.1 ml of a 10% by weight sodium dispersion in toluene. When acetone/sodium precipitates as a white compound, then 25.0 gm (0.41 mole) ethylene sulfide is added. The exothermic polymerization starts immediately and the polymer precipitates as a fine powder while the temperature rises to cause refluxing of acetone. In 10 min the polymerization is complete and 200 ml of 10% HCl is added followed by a 15 min agitation period. The polymer is filtered, washed with water, and dried under reduced pressure at 50°C to give 24.8 gm (99%) of poly(ethylene sulfide) as a colorless powder, m.p. 211°C. The specific viscosity of a 0.5% DMSO solution at 175°C is 1.30 corresponding to a reduced viscosity of 60 ml/gm. The flexural strengths of test specimens of the polymer are 9,00()-l 97,000 Ib/in. ... 

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

Ethylene sulfide (Thiirane Thiacyclopropane) 55-6 14914 1 0046 Polymerizes rapidly... 

The stereoelectivity ratio was not modified when running a copolymerization reaction in the presence of achiral monomer e.g, ethylene sulfide. This confirms again the strong catalyst control process involved in these polymerization. 

As indicated above, cyclic sulfides, such as propylene sulfide, were used as monomers in the synthesis of block copolymers. Other cyclic sulfides, such as ethylene sulfide, trimethylene sulfide (thiacyclobutane), and 2=methylthiacyclobutane were l1so polymerized by organolithium initiators to yield either rubbery or crystalline block copolymers. In the course of this work, some interesting new light was thrown on the mechanism of the reaction between organolithium and cyclic sulfides, as illustrated below. 

The parent compound, thiirane (ethylene sulfide), produces a crystalline polymer with a melting point of 205 °C that is insoluble in most solvents.As a consequence, the polymerizations of this monomer are heterogeneous and mechanistic studies are difficult. The most studied monomer is methylthiir-ane (MT) often referred to as propylene sulfide. However, other substituted thiiranes have also been described extensively in the literature. The polymerizations can occur by cationic, anionic, coordinative, and monomer insertion mechanisms. 

It is well known that mercury can form polymeric structures with sulfur-containing ligands where the ratio of the ligand to merciny is less than the 2 1 found in the isolated complex, Hg(S2CNR2)2. Finally, it should be pointed out that the captured mercury on WP-3 resists leaching even with lOM hydrochloric acid, as with WP-1, which is modified with ethylene sulfide. 

The polymerization of monomers with unbalanced enantiomeric composition was performed using achiral initiators in the case of propylene oxide [13, 29] and propylene sulfide [24, 29]. In both cases it was shown that the optical activity of nonpolymerized monomer was identical to that of the initial monomer introduced. This seems to eliminate, at least in these cases, a possible chain effect. Furthermore, in the copolymerization of propylene oxide [30] and propylene sulfide [31] with achiral monomers, such as ethylene oxide and ethylene sulfide using chiral initiators, the stereoelectivity ratio is not affected by the achiral comonomer. If an end-chain effect exists, a decrease of stereoelection should be observed with the incorporation of achiral ethylene oxide or ethylene sulfide units. 

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