Sulfur Containing Monomers

isobutyl, and phenyl vinyl sulfide behave as typical good electron-donating monomers, readily undergoing alternative copolymerization with a strong electron acceptor such as Vinyl sulfide-MA mixtures 

Similar to furan and benzofuran monomers,thiophene and 1-benzothiophene are also known to copolymerize in a 1 1 fashion with MA. Thiophene will not undergo free-radical homopolymerization or copolymerization with monomers such as styrene, methyl methacrylate, or acrylonitrile. However, when an equimolar mixture of thiophene and MA are combined with chloroform containing AIBN and heated at 60°C, a white copolymer starts to precipitate after only a few minutes reaction time. Varying the molar feed ratios showed that both yields and reduced viscosities were maximum for equimolar feeds. Copolymerizations in solution from 1 bar to 3 kbars show that rates and yields are increased with pressure.Through composition studies and comparing the NMR spectrum of the copolymer with the NMR spectra of 2,3- and 2,5-dihydrothiophene, structure 88 was assigned to the copolymer. 

By analogy with furan-MA copolymerizations/ propagation is believed to occur by the thiophene-MA which has an equilibrium 

Under the influence of AIBN, benzothiophene and indole also form alternating copolymer with Varying the molar feed ratios, it was 

Several vinyl, propenyl, and isopropenyl substituted thiophenes, with halogen substituents, have also been mixed with MA and copolymerized, using peroxides at 65-70°C. The structures of the various copolymers were not reported. However, use of equimolar feeds would suggest that some of the copolymers could be of the alternating type. Copolymerization of 4-methyl-5-vinylthiazole-MA mixtures was also studied.Alternating copolymers were also probably formed from this comonomer pair. 

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Cyclic Polymers from Sulfur Containing Monomers. 167... 

Sulfur-containing spiro orthocarbonates, cationic polymerization of, 23 729 Sulfur-cured EPDM, 21 8041. See also Ethylene- propylene-diene monomer (EPDM) rubber Sulfur deposits... 

Polycarpamines A-E (137-141) are unusual sulfur-containing antifungal agents from Polycarpa auzata from the Philippines. The structures were elucidated by interpretation of spectral data [148]. Polycarpine (142), a cytotoxic, dimeric, disulfide alkaloid, the corresponding dihydrochloride (143) and two sulfur-containing related monomers (144-145) were isolated from Polycarpa clavata from Western Australia [149]. Polycarpine (142) was also isolated with two monomers (144,146) from P. auraia from Chuuk [150] and later it was synthesised in three steps from p-methoxyphenacyl bromide [151]. 

Title Use of Sulfur Containing Initiators for Anionic Polymerization of Monomers... 

The polymeric phosphazenes are treated in chapter (see Polyphosphazenes) A recent monograph covers the chemistry of polyphosphazenes (nomenclature, synthesis of cyclic monomers , ring opening polymerization, condensation polymerization, substitution, polymer properties, and applications more than 1000 literature citations). Other reviews have also been published recently. Sulfur-containing polyphosphazenes have also been described. ... 

Kinetic analysis gives additional information related to the reactivity of the free radicals obtained during the processes following a photoinduced electron transfer process. A variation in radical reactivity could be caused, for example, by their stability or their reactivity with monomer, as in the case of photoinitiation by 4-carboxybenzophenone-sulfur-containing carboxylic acid of free-radical polymerization [184]. 

The polymers obtained by polymerization of cyclic sulfides have no commercial importance. A monomer can be obtained from pentaerythritol, C(CH20H)4, and chloroacetaldehyde, CICH2CHO, which leads to sulfur-containing polymers when polycondensed with disodium sulfide ... 

The limiting viscosity number is determined in m-cresol or concentrated sulfuric acid. The polyamide-6 (Nylon-6) so obtained has a crystallite melting point around 216°C. It still contains monomer and low-molecular-weight cyclic oligomers which can be removed by extraction with water or lower alcohols. These oligomers can be separated and identified chromatographically (see Example 4.9). 

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