Sulfur-containing polymers. X. Aromatic poly(sulfenyl thiocarbonates)

Aromatic poly(sulfenyl thiocarbonates) have been synthesized by the interfacial polycondensation of bis(dithiocarbonyl chlorides) with bisphenols. Bisphenols having the hydroxyl groups on separate rings gave polymers in high yields. The inherent viscosities of the polymers ranged from 0.22 to 0.51. In general, they were soluble in chloroform, sym-tetrachloroethane, hexamethylphosphoramide, m-cresol, and dimethylformamide and formed transparent tough films on evaporation of chloroform solutions. Almost all of the polymers were amorphous and gave melt-spun fibers. The polymer films decomposed upon ultraviolet irradiation with liberation of carbonyl sulfide.     

Sulfur-containing polymers. VIII. Preparation and properties of poly(carbamoyl disulfides)

Poly(carbamoyl disulfides) have been prepared for the first time by the stepwise condensation of chlorocarbonylsulfenyl chloride with dithiols and diamines. The polymers obtained in high yields had inherent viscosities up to 1.86. The properties of the polymers depended primarily on the kind of diamines used. Some of the polymers gave transparent, tough films from chloroform solution. The polymer films decomposed by ultraviolet irradiation with liberation of carbonyl sulfide. All the polymers gradually became brittle during storage for 6–8 months under diffused light.     

Solution properties of poly(thiocarbonates)

For a series of poly(thiocarbonates) derived from bisphenol A several conformational and thermodynamic solution properties (partial specific volume, refractive index increment, effective dipole moment and characteristic ratio) were summarized. The effect of the structure, size and polarity of the different poly(thiocarbonates) side chains on these properties were analyzed. The high rotational freedom of the poly(thiocarbonate) chains, obtained from theoretical calculations, justifies the variation of the different properties experimentally obtained in the studied polymers.     

Sulfur-containing polymers. VI. Preparation of poly[alkylene bis(oxycarbonyl) disulfides] and related polymers

Poly[alkylene bis(oxycarbonyl) disulfides] have been prepared for the first time by the reductive coupling of alkylene bis(oxycarbonylsulfenyl chlorides). Potassium iodide and a variety of transition metals or their salts were employed as reducing agents. Of these potassium iodide and cuprous chloride gave the best results. Pyrolysis, desulfurization. and thiol-induced fragmentation of the polymers have been studied. Homologous polymers, i.e., monosulfide polymer, trisulfide polymer, and tetrasulfide polymer, have been also synthesized. Monosulfide and disulfide polymers were highly crystalline solids. Trisulfide polymer was a white solid with a low degree of crystallinity. These polymers were soluble in chloroform and dichloromethane. Tetrasulfide polymer was a crystalline yellow solid and was soluble only in HMPA.     

Sulfur-containing polymers. XVIII. Preparation and properties of thiuram polysulfide polymers

Thiuram polysulfide polymers have been prepared from alkali metal bisdithiocarbamates either by oxidation with ammonium persulfate or by polycondensation with sulfur chlorides. In some cases, isothiocyanate formation and/or thiourea formation were noticed. The polymer properties were significantly affected by the diamines used. Polymers derived from p-phenylenediamine decomposed gradually at room temperature with the liberation of elemental sulfur. Polymers based on aliphatic primary diamines were more stable. Piperazine gave the most stable polymer.     

Sulfur-containing polymers. II. Preparation and properties of polycarbamoylsulfenamides

Polycarbamoylsulfenamides have been prepared by interfacial and solution polycondensation of chlorocarbonylsulfenyl chloride with diamines. In preparing the polycarbamoylsulfenamides, the following types of diamines were used: primary aliphatic diamines, a mixed primary-secondary aliphatic diamine, primary aromatic diamines, and secondary aromatic diamines. The properties of the resulting polymers depended primarily on the kind of diamines used. Transparent, tough films were obtained from the polymer based on N,N′-dimethyl-4,4′-diaminodiphenylmethane. The photochemical decomposition of the polymers has been studied.     

Sulfur-containing polymers. Synthesis and properties of novel poly(arylene thioether)s based on 2,2-bis(4-mercaptophenyl)propane

Novel poly(arylene thioether)s were synthesised using the one pot polymerisation method from the bis(N,N-dimethyl-S-carbamate) of 2,2-bis(4-mercaptophenyl)propane and activated difluoro aromatic compounds. Each of the polymers, obtained in good yields and with fairly high molecular weights, were characterised by IR, GPC and NMR analyses. In particular, the NMR characterisation was performed using ¹H NMR, ¹³C NMR, DEPT, 2D COSY and 2D HSQC experiments. To study the effect on the thermal properties of replacing the ethereal oxygen atoms with sulfur atoms, we have synthesised the counterparts, the poly(arylene ether)s, with similar molecular weights. We observed that the substitution of the ethereal oxygen atoms with sulfur atoms results in a slightly lower thermal stability for the poly(thioether ketone)s, both under nitrogen and in air, and does not modify the T_g values. For the poly(thioether sulfone), on the other hand, the thermal stability is equal to that of the poly(ether sulfone), while the T_g is 10 °C lower. Furthermore, each sample is completely amorphous, with the exception of one of the poly(thioether ketone)s (sample 1b), which shows the capacity to crystallise, even if with a very slow crystallisation kinetics.     

Dielectric relaxations in poly(thiocarbonates)

The dielectric absorptions observed on six poly(thiocarbonates) (PTC) containing different substituents in the interphenylic carbon atom are subjected to a study. The α relaxation process associated with the glass transition temperature, which appears at the highest temperature studied, is overlapped with a strong conductive component. Between 80 and 100°C dielectric activity (β) is observed, which is related to structural relaxation phenomena. Polymers with double substitution on the interphenylic carbon atom show a γ relaxation with an activation energy of ca. 11 kcal mol^?1 while those where the carbon atom is linked to a cyclohexyl group show higher activation energies and their respective characteristics. A cryogenic absorption around ?120°C, for at least three polymers with an activation energy of about 5 kcal mol^?1, is detected. © 1994 John Wiley & Sons, Inc.     

Thermosensitive and redox-active polymers: Preparation and properties of poly(N-ethylacrylamide-co-vinylferrocene) and poly(N,N-diethylacrylamide-co-vinylferrocene)

Thermosensitive and redox-active polymers were prepared by copolymerization of N-ethyl- or N,N-diethylacrylamides with vinylferrocene (VFc). LCST (lower critical solution temperature) of the aqueous copolymer solution was decreased by increasing the ferrocene content in the copolymer. The oxidation of ferrocene led to a significant increase in LCST due to the transition from hydrophobic to hydrophilic character of the ferrocene moiety in the copolymer. The ferrocene content in the copolymer increases with increasing differences between the LCST's of the oxidation and reduction states. The transition could be made reversible by redox reaction using L -ascorbic acid as an oxidant and cerium sulfate as a reductant. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 1967–1972, 1997     

Sulfur-containing polymers. V. Preparation of polyoxycarbonylsulfenamides by polycondensation of bis(oxycarbonylsulfenyl chlorides) with diamines

Polyoxycarbonylsulfenamides (POSA) have been prepared by interfacial polycondensation of bis(oxycarbonylsulfenyl chlorides) with diamines. The polymers obtained ranged in physical form from crystalline solids to resinous materials depending on the kind of both bis(oxycarbonylsulfenyl chlorides) and diamines used. Some of the polymers gave transparent pliable films from chloroform solution. The polymer films decomposed with liberation of carbonyl sulfide on being subjected to ultraviolet radiation.     

Nonlinear optical properties of poly(arylenevinylene) polymers

This paper concerns investigations of the third order nonlinear optical response of poly(arylene vinylene) polymers and in particular precursor route poly(p-phenylene vinylene) [PPV]. Results for photoexcitation measurements provide information on the response time and the nature of the nonlinearity in the single-photon resonant excitation regime. Transmission third harmonic generation [THG] measurements yield complimentary information on the single-photon non-resonant regime.     

Preparation and properties of poly(phosphonatoalanes)

Two general types of poly(phosphonatoalanes), [? Al(X)O? P(O)(R)O? ]_n (X = Cl or F, R = alkyl or aryl) and [? Al(OP(O)R₂)O? P(O)(R′)O? ]_n, were prepared and studied. Poly[chloro(phosphonato)alanes] are influsible and have low molecular weights (n = 4–11). Polyfluoro(phosphonato)alanes are fusible and also have low molecular weights, but under certain conditions grow to higher polymers (n = 30–45). Poly[phosphinato(phosphonato)alanes] are fusible and are prepared with high molecular weights (n = 83–340).     

Degradation of polymer mixtures. IV. Blends of poly(vinyl acetate) with poly(vinyl chloride) and other chlorine-containing polymers

The degradation of the binary polymer blends, poly(vinyl acetate)/poly(vinyl chloride), poly(vinyl acetate)/poly(vinylidene chloride) and poly(vinyl acetate)/polychloroprene has been studied by using thermal volatilization analysis, thermogravimetry, evolved gas analysis for hydrogen chloride and acetic acid, and spectroscopic methods. For the first two systems named, strong interaction occurs in the degrading blend, but the polychloroprene blends showed no indication of interaction. In the PVA/PVC and PVA/PVDC blends, hydrogen chloride from the chlorinated polymer causes substantial acceleration in the deacetylation of PVA. Acetic acid from PVA destabilizes PVC but has little effect in the case of PVDC because of the widely differing degradation temperatures of PVA and PVDC. The presence of hydrogen chloride during the degradation of PVA results in the formation of longer conjugated sequences, and the regression in sequence length at high extents of deacetylation found for PVA degraded alone is not observed.     

Sulfur-containing polymers. VII. Alternating copolydisulfides

A variety of copolydisulfides have been synthesized in high yields by the fragmentation polymerization of bis(sulfenyl thiocarbonates) with dithiols in the presence of triethylamine. The structures of the copolymers were investigated by x-ray and NMR studies. Alkylene–arylene copolydisulfides were alternating. Alkylene–arylene copolymers derived from arylene dithiols were alternating, and those prepared from alkylene dithiols were generally random. It was concluded that the present procedure makes it possible to prepare various kinds of alternating copolydisulfides by using appropriate combinations of a bis(sulfenyl thiocarbonate) and a dithiol.     

Preparation and properties of poly(imide-oxoisoindolobenzothiadiazine dioxides)

New thermally stable poly(imide-oxoisoindolobenzothiadiazine dioxides) (PIOD) have been prepared by the three-step cyclopolycondensation reaction of diaminobenzenesulfonamides with aromatic tetracarboxylic dianhydrides. The polymerization proceeded through the formation of poly(amic acid-sulfonamides) (PAAS), followed by cyclodehydration to yield polyimide-sulfonamides (PIS), which were subsequently converted to PIOD at 300°C. PAAS having inherent viscosities in the range of 0.1–0.5 in N-methyl-2-pyrrolidone (NMP) were obtained in approximately quantitative yield. PIOD were insoluble in most organic solvents, whereas PAAS and PIS were soluble in NMP and dimethyl sulfoxide. Differential thermal analysis and thermogravimetric analysis indicated that PIOD began to decompose at 460°C in air. The cyclodehydration of the model compounds was also investigated.     

Preparation and properties of poly(methylene terephthalates)

A systematic study of poly(methylene terephthalates) has been made. Melting points, second-order transition temperatures, and solubility temperatures are presented for the homologous series of terephthalate polyesters of ethylene glycol through 1,10-dodecanediol, and for terephthalate copolyesters of: (1) ethylene glycol/1,3-propanediol and (2) ethylene glycol/1,4-butanediol. Fiber properties of the terephthalate polyesters and the 70/30 ethylene glycol/1,3-propanediol copolyterephthalate ester are presented. Only the first three members of the poly(methylene terephthalate) series show promise for use in textile fibers.     

Preparation and photophysical properties of halogenated silicon(IV) phthalocyanines substituted axially with poly(ethylene glycol) chains

A series of silicon(IV) phthalocyanines with two axial poly(ethylene glycol) chains SiPcX₈[(OCH₂CH₂)_nOCH₃]₂ (X=H, Cl, Br; n≈16) have been prepared of which the photosensitizing properties are enhanced as the periphery of the macrocycle is substituted with heavier halogens.     

Viscoelastic properties of heterogeneous network polymers from poly(D-glutamic acid) and poly(oxyethylene glycol)

A series of five heterogeneous network polymers was prepared from poly(D -glutamic acid) (PDG) and poly(oxyethylene glycol) (PEG), and their dynamic mechanical properties were studied. The content of PDG was fixed at 60% by weight, and the molecular weight of PEG was changed to obtain networks with various crosslink densities. An increase in the PEG molecular weight from 330 to 880 caused considerable broadening of tan δ and E″ curves, and peak temperatures for tan δ and E″ decreased slightly. Curves of tan δ and E″ for PDG–PEG 4000 (indicating a PEG component of molecular weight 4,000) were much broader and the existence of two peaks was recognized. These findings and x-ray photographs suggest that PDG–PEG 330, 570, and 880 give films of fairly uniform phase, but that PDG–PEG 1830 and 4000 give films with two-phase structure. The factors influencing the dynamic mechanical properties in decreasing order of effectiveness are found to be the proportions by weight of PDG and PEG, the compatibility of PDG with PEG, the crosslink density, and the concentration of free carboxyl groups. The infrared spectra of these polymers indicate that at least part of the PDG component retains the α-helix conformation.