Novel synthetic approach to poly(p-benzenesulfonamide): Self-polycondensation of active p-aminobenzenesulfonic acid derivatives under mild conditions

Three active p-aminobenzenesulfonic acid derivatives, 1-(p-aminobenzenesulfonyl)imidazole ( 4a ), 1-(p-aminobenzenesulfonyloxy)benzotriazole ( 4b ), and 2-phenyl-4-(p-aminobenzenesulfonyl)-1,3,4-oxadiazoline-5-thione ( 4c ) were synthesized by reacting p-isocyanatobenzenesulfonyl chloride ( 1 ) with stoichiometrical quantities of water in the presence of dibutyltin didodecanoate and subsequently with imidazole, 1-hydroxybenzotriazole and 2-phenyl-1,3,4-oxadiazoline-5-thione, respectively. The self-polycondensation of 4a–c , leading to poly(p-benzenesulfonamide) ( 7 ), was carried out in solution using polar aprotic solvents, N-methyl-2-pyrrolidone (NMP) and hexamethylphosphoric triamide (HMPA), and acidic media, dimethyl sulfoxide (DMSO) and m-cresol, with or without an appropriate acid catalyst or acid acceptor under mild conditions. Poly(p-benzenesulfonamide) having the highest reduced viscosity of 0,14 dl·^?1 was obtained almost quantitatively from 4c by using m-cresol as a solvent without any acid catalyst and acid acceptor at 25°C. The polymers are soluble in polar aprotic solvents such as NMP, HMPA and DMSO and in aqueous sodium hydroxide. These poly(p-benzenesulfonamide)s are less thermally stable than completely aromatic polyamides, because the initial weight-loss started at 250–350°C. Aminolysis of three benzenesulfonic acid derivatives, 1-benzenesulfonylimidazole ( 5a ), 1-benzenesulfonyloxybenzotriazole ( 5b ), and 2-phenyl-4-benzenesulfonyl-1,3,4-oxadiazoline-5-thione ( 5c ), with the same leaving groups was also carried out as a model reaction of self-polycondensation to determine the reaction conditions.     

Synthesis of poly(chalcone)s by polycondensation of aromatic dialdehydes with aromatic diacetyl compounds

Poly(chalcone)s were prepared by polycondensation of aromatic dialdehydes with aromatic diacetyl compounds in methanesulfonic acid (MSA) or phosphorus pentoxide/methanesulfonic acid (PPMA). Polycondensations proceed smoothly at room temperature and produced poly(chalcone)s with inherent viscosities up to 0,97 dL · g^?1. The reaction of acetophenone with aromatic aldehydes in MSA or PPMA was studied in detail to demonstrate the feasibility for polymer formation. Poly(chalcone)s are only soluble in concentrated sulfuric acid and methanesulfonic acid at room temperature. Thermogravimetry of poly(chalcone)s showed 10% weight loss around 380 and 420°C in air and under nitrogen, respectively.     

Synthesis and Characterization of New Cardo Polyamides and Polyimides bearing a 4‐Phenylcyclohexylidene Unit

A new cardo diamine monomer, 1,1‐bis[4‐(4‐aminophenoxy)phenyl]‐4‐phenylcyclohexane bearing a 4‐phenylcyclohexylidene unit, was prepared in three steps from 4‐phenylcyclohexanone. The monomer was reacted with various aromatic dicarboxylic acids and tetracarboxylic dianhydrides to produce novel polyamides and polyimides, respectively. The polyamides were prepared utilizing Yamazaki reaction conditions with inherent viscosities of 0.62–0.98 dL·g^–1. The polyimides were prepared by a two‐stage procedure that included a ring‐opening polyaddition to give poly(amic acid)s, followed by thermal or chemical cyclodehydration. By chemical cyclodehydration, the obtained polyimides had inherent viscosities of 0.61–0.93 dL·g^–1. Most of the polymers dissolved in N‐methyl‐2‐pyrrolidinone, N,N‐dimethylacetamide, N,N‐dimethylformamide, dimethyl sulfoxide, pyridine, and cyclohexanone. These polymers showed glass transition temperatures between 225–312°C and decomposition temperatures at 10% weight loss temperatures ranging from 470–500°C and 480–510°C in nitrogen and air atmosphere, respectively. These tough and flexible polymer films had a tensile strength of 81–124 MPa, an elongation at break of 8–21%, and tensile modulus of 2.0–2.8 GPa.     

Über den grundkörper der polynitrile,das poly(methinimin)

The thermally induced ring-opening polymerization of 1,3,5-triazine-methalhalide-complexes leads to poly(methinimine), the parent compound of polynitriles. The thermodynam+ of the reaction are examined and the reaction is controlled by mass spectrometry. The semiconductive properties (σ_300K up to 10^?10 Ω^?1 cm^?1) and the thermal analyses of the polymers are described.     

Synthetic polymers containing sugar residues, 2. Synthesis and properties of poly(urea-urethane)s derived from D-glucosamine and diisocyanates

Poly(urea-urethane)s containing D-glucosamine residues in the main chain were prepared by direct addition polymerization of D-glucosamine and diisocyanates. The polymerization reaction proceeded smoothly in N,N-dimethylacetamide or hexamethylphosphoric triamide under certain conditions without blocking the excess hydroxy groups. The resulting poly(urea-urethane)s were all soluble in polar solvents and had inherent viscosities of up to 1,27 dl·g^?1. These polymers had D-glucosamine residues with three pendant hydroxy groups in each unit, and they exhibited good reactivity toward acetylation and also very high water absorption.     

Synthesis and characterization of 1,3,4-oxadiazole-containing polyethers from 2,5-bis(4-fluorophenyl)-1,3,4-oxadiazole and various aromatic diols

Six 1,3,4-oxadiazole-containing polyethers with reduced viscosities of 0,65–1,17 dL · g^?1 were synthesized by high-temperature solution polycondensation of an activated difluoride, 2,5-bis(4-fluorophenyl)-1,3,4-oxadiazole, with aromatic diols possessing a variety of ring structures. The expected chemical structures were confirmed by IR and ¹H NMR spectroscopy and elemental analysis. Of all the polymers, two polyethers were highly crystalline and soluble only in limited solvents such as o-chlorophenol and conc. sulfuric acid. The other polyethers were amorphous and dissolved readily in a variety of organic media including polar aprotic solvents, phenols and chlorinated hydrocarbons. Colorless to slightly yellow-colored, transparent and tough films could be cast from the N-methyl-2-pyrrolidone or o-chlorophenol solutions. The mechanical properties were excellent and their tensile strength, elongation at break and tensile moduli were in the ranges of 53–80 MPa, 4–12% and 1,3–2,0 GPa, respectively. The amorphous polyethers had high glass transition temperatures of 195–259°C. All the polyethers were highly thermally and thermooxidatively stable and exhibited no weight loss up to 400°C, with 10% weight loss being recorded at 464–514°C in air.     

Ionic conduction of cross-linkable oligo(oxyethylene)-branched poly(phosphazene)

A new cross-linkable polyphosphazene [AEP7] in which allyl groups were introduced at the ends of the etheric side chains of the polymer was prepared. The LiClO₄/AEP7 hybrids showed relatively high ionic conductivity of 7,9·10^?5 S·cm^?1 at 25°C with 6 wt.-% of LiClO₄. The ionic conductivity of the hybrids remained unchanged before and after cross-linking by UV-irradiation. The dimensional stability or the mechanical strength of the hybrids was improved upon cross-linking. Additionally, the cross-linked AEP7(29)/propylene carbonate (PC)(60)/LiClO₄(11) (wt.-%) hybrids, in which PC was used as a plasticizer, showed an ionic conductivity as high as 3,1·10^?3 S·cm^?1 at 25°C.     

Preparation and properties of polyaniline doped with poly(thiophenylenesulfonic acid)

A novel polyaromatic acid, poly(thiophenylenesulfonic acid) (PTPSA), prepared from a soluble precursor of poly(arylenesulfonium salt) was employed as a dopant for polyaniline (PAn). The electro-oxidative polymerization of aniline in PTPSA aqueous solution gives an electroactive PAn/PTPSA composite with three redox couples at 0.16, 0.53, and 0.71V (vs. SCE). Composites of different molar ratio ([SO₃H]/[An] = 0.10, 0.21, 0.42, 0.50, 0.83, 1.67) was prepared in order to confirm the transformation from the emeraldine base to its PTPSA salt, where a quantitative doping reaction was observed by means of UV-VIS and IR measurements. The thermogravimetric analysis revealed that the composites do not decompose up to 200°C in nitrogen atmosphere. The composite ([SO₃H]/[An] = 0.50) shows an electrical conductivity of 1.5 S·cm^–1 at 30°C and 3.0×10^–1 S·cm^–1 at 170°C. The composite retains its conductivity after heating at 150°C for 24 h.     

Synthesis and characterization of some poly[nitrilo-bis(phenylamino)phosphoranetriyl]s

Poly[nitrilo-bis(phenylamino)phosphoranetriyl]s ( 3a–d ) were synthesized and characterized in dilute solution and in the solid state. The synthesis was accomplished by thermal polymerization of of 2,2,4,4,6,6-hexachloro--triazatriphosphorane ( 1 ) at 240°C, followed by the reaction of the soluble product, poly(nitrilodichlorophosphoranetriyl) ( 2 ), with aniline or its derivatives. Elemental analyses show the presence of some residual chlorine, which, according to the IR spectra, does not seem to be ascribed to an incomplete substitution. All the polymers have intrinsic viscosities in tetrahydrofuran higher than 100ml g^?1, and high weight average molecular weights (M _w ≥ 7 · 10⁵). The molecular weight distribution is very broad (M _w/M _n ≥ 13,4) which could suggest either a branched structure or a complex mechanism of polymerization. From DSC measurements the glass transition temperatures are found to be between 70 and 98°C and the related values of specific heat increments, ΔC_,p, are between 0,13 J g^?1 K^?1 and 0,27 J g^?1 K^?1; the densities are in the order of 1,3 g ml^?1.     

Synthesis of poly(2-ethyl-2-hydroxymethyltrimethylene carbonate)

2-Ethyl-2-hydroxymethyltrimethylene carbonate (5-ethyl-5-hydroxymethyl-1,3-dioxan-2-one) ( 1 ) was treated with trimethylsilyl chloride, benzyl chloroformate and phenyl isocyanate to give the corresponding 5,5-disubstituted 1,3-dioxan-2-ones 2 , 3 and 4 . These monomers were subjected to anionic ring-opening polymerization reactions with lithium alcoholates as initiators. The polymers obtained usually exhibit linear structure; under special conditions slightly branched polymers were obtained. Poly( 2 ) and poly( 3 ) were subjected to polymer-analogous reactions—hydrolysis and hydrogenation—by which the protective groups are removed and poly( 1 ) was obtained. The hydroxyl groups in poly(1) are susceptible to a polymer-analogous reaction. Poly( 4 ) obtained by reaction of poly( 1 ) with phenyl isocyanate was identical with poly( 4 ) obtained by ring-opening polymerization of the corresponding monomer 4 . All these new monomers were characterized by means of ¹H and ¹³C NMR spectroscopy as well as elemental analysis. The polymers were analyzed with respect to their primary structure, their molecular weight and molecular weight distribution. The thermal properties of some of the polymers are discussed.     

Aqueous polymerization of vinyl monomers in the presence of surfactants, 3. System: Acrylamide/poly(butyl acrylate) latex

The kinetics of the polymerization of acrylamide initiated by potassium peroxodisulfate in aqueous medium is studied in the presence of poly(butyl acrylate) latex. The rate of acrylamide polymerization increases with the concentration of the latex in the reaction system. The increase is especially pronounced at concentrations of solid latex higher than 100 g per dm³ of polymerization mixture. The activation energy of the acrylamide polymerization in the presence of poly(butyl acrylate) latex is 85,8 kJ · mol^?1. This value is substantially higher than the value of 70,7 kJ · mol^?1 found for the activation energy of the polymerization of acrylamide in the absence of poly(butyl acrylate) latex. A set of reactions is proposed and the equation describing the simultaneous homopolymerization of acrylamide and grafting of poly(butyl acrylate) latex with acrylamide is derived.     

Synthesis of aromatic polyamides from reactive N,N′-isophthaloyldi(thiolactam)s and aromatic diamines under mild conditions

Solution condensation polymerization of new reactive diamides, N, N′-isophthaloyldipyrrolidine-2-thione ( 1a ) and N, N′-isophthaloyldiperhydroazepine-2-thione ( 1b ), with aromatic diamines 2 in 1-methyl-2-pyrrolidone at room temperature or above leads to polyamides 3 with moderate molecular weights. The ease of aminolysis of these diamides is discussed in relation to the good leaving nature of the thiolactam moieties and an intramolecular general base catalysis. The condensation polymerization is strongly catalyzed by 1-hydroxybenzotriazole giving aromatic polyamides with higher inherent viscosities up to 0,9 dl.g^?1.     

Synthesis and characterization of multiblock copolymers poly[poly(L-lactide)-block-polydimethylsiloxane]

The preparation of multiblock copolymers poly[poly(L -lactide)-block-polydimethylsiloxane] by polycondensation of bifunctional oligomers via hydrosilylation is described. The procedure consists first to synthesize the two bifunctional oligomers α,ω-disilyl-polydimethylsiloxane and α,ω-diallyl-poly(L -lactide). The former is prepared in one step by cationic polymerization of octamethylcyclotetrasiloxane in the presence of 1,1,3,3-tetramethyldisiloxane as end-blocker. Two steps are necessary to prepare α,ω-diallyl-poly(L -lactide). The first one is the polymerization of L-lactide initiated by the system ethylene glycol/tin 2-ethylhexanoate. In a second step, the hydroxyl end-groups of the resulting α,ω-dihydroxy-poly(L -lactide) are transformed, by reaction with allyl isocyanate, into terminal allylic functions. Different multiblock copolymers were prepared by hydrosilylation (catalyzed by hexachloroplatinic acid) using the same α,ω-diallyl-poly(L -lactide) (M?_n = 2000 g · mol ^?1) and various α,ω-disilyl-polydimethylsiloxanes (M?_n from 1 750 to 9 000 g · mol ^?1). The influence of parameters such as temperature, stoichiometry of reactive end-groups and catalyst concentration on the molecular weight of the copolymers was studied. High molecular weight copolymers were obtained (DP_n > 12 by SEC). In addition to the biodegradability of the lactic acid units, the immiscibility of the polydimethylsiloxane and poly(L -lactide) blocks imparts thermoplastic elastomer properties to these copolymers. The crystallinity of the poly(L -lactide) phase is dependent on the molecular weight of the polydimethylsiloxane blocks.     

Molecular size and configuration of poly(3-vinylpyrene)

Solution properties of poly(3-vinylpyrene) (PVπ) have been studied to determine the degree of hindrance to the flexibility of the vinyl chain by the pyrene pendant group. Fractionation of this polymer prepared by anionic polymerization, yielded nine narrow distribution fractions in the M_w range of 35 000–490 000 and the fractions were characterized by osmometry, light-scattering and viscometry. Intrinsic viscosities of the fractions were obtained in chloroform and tetrahydrofuran at 25°C and in o-dichlorobenzene at different temperatures from 25–80°C. From the KUHN-MARK-HOUWINK relationship, [η] = KM^a, K and a values were determined and the exponent varied in the order, chloroform (a = 0.500) < tetrahydrofuran (a = 0.547) < o-dichlorobenzene (a = 0.655) suggesting that chloroform at 25°C is a theta solvent for PVπ. Cloud point titration indicated that a mixture of THF/methanol in the ratio of 92:8 (V/V) is also a theta solvent for PVπ at 25°C. A K_Θ value of 5.2·10^?4 determined for PVπ at 25°C gave a value for the unperturbed dimension (R /M)^1/2 of 5.77·10^?9 cm. The conformational parameter, σ was computed as 2.84 for PVπ which suggests that the hindrance to rotation of the vinyl chain by the pyrene group is approximately the same as in the case of carbazole in poly(n-vinylcarbazole). Values of [η] in o-dichlorobenzene decreased with the increase of temperature yielding an average negative d log [η]/dT value of 1.1·10^?3. The expansion factor decreased in all cases with the rise of temperature. A decrease of unperturbed dimension with the increase of temperature was reflected in the d log K_Θ/dT value of ?2.0·10^?3 from which (R /M)^1/2 at 80°C was computed as 5.35·10^?9 cm.     

Influence of chemical structure on glass transition temperatures of poly(propylene terephthalate) and poly(propylene isophthalate)

Poly(propylene terephthalate)

1 Systematic IUPAC name: poly(oxypropyleneoxyterephthaloyl).

(PPTP) and poly(propylene isophthalate)

2 Systematic IUPAC name: poly(oxypropyleneoxyisophthaloyl).

(PPIP) were prepared by melt polycondensation. Different fractions with number-average molar masses in the range 5 000 ? 20 000 g·mol^?1 were obtained and their respective glass transition temperatures (T_g) determined by calorimetry. The solubility parameters of the polymers were obtained by viscosity measurements in different solvents and were found to be 9,4 and 9,5 cal^1/2·cm^?3/2 (19,2·10³ and 19,4·10³ J^1/2·m^?3/2) for PPIP and PPTP, respectively. The glass transition temperatures were compared with those reported for analogous polyesters and it was shown that intramolecular interactions highly influence the T_g of these polyesters, whereas the effect of intermolecular interactions seems to be less important.     

Synthesis and characterization of new polyamides and polyimides prepared from 2,2-bis[4-(4-aminophenoxy)phenyl]adamantane

In this work, we synthesized a new diamine containing a pendant adamantane group and a flexible aryl ether unit, 2,2-bis[4-(4-aminophenoxy)phenyl]adamantane ( BAPA ) in three steps starting from 2-adamantanone. A series of new polyamides having inherent viscosities of 0.72–0.90 dL·g^–1 were prepared by direct polycondensation with aromatic dicarboxylic acids using triphenyl phosphite and pyridine as condensing agents. All polymers revealed an amorphous nature and were almost readily soluble in a variety of polar solvents. The glass transition temperature of these polyamides range from 254–294°C. The polyamides remain fairly stable up to a temperature around 450°C and lose 10% weight between 490 and 524°C in nitrogen atmosphere. A series of new polyimides were also synthesized from BAPA and various aromatic tetracarboxylic dianhydrides by the conventional two-step method. The inherent viscosities of polyimides were in the range of 0.66–0.77 dL·g^–1. The polyimides are amorphous and have glass transition temperatures between 276 and 310°C. Thermogravimetric analyses demonstrated that almost all polymers are stable up to 450°C, and the 10% weight loss temperatures were recorded in the range of 515 to 541°C in nitrogen.     

Synthesis and characterization of new soluble aromatic poly(ureaimide)s from N,N′-dimethyl-N,N′-bis(aminophenyl)ureas and aromatic tetracarboxylic dianhydrides

New poly(urea-imide)s having inherent viscosities of 0.26–0.57 dL/g were synthesized in two steps by ring-opening polyaddition of N,N′-dimethyl-N,N′-bis(aminophenyl)ureas to various aromatic tetracarboxylic dianhydrides giving poly(amic acid)s, followed by thermal cyclodehydration. All the poly(urea-imide)s showed amorphous patterns in the wide angle X-ray diffractograms. Most of the poly(urea-imide)s were soluble in organic solvents, especially phenolic solvents such as m-cresol and o-chlorophenol, and the polymers synthesized from the 3,4′-type diamine were more soluble than those from the 4,4′-type monomer. The glass transition temperatures and 10% weight loss temperatures under nitrogen of the poly(urea-imide)s were in the range of 218–263°C and 455–500°C, respectively.     

Polymerization of lactams, 54. Anionic polymerization of 2-pyrrolidone accelerated with CO2, part 3

Intrinsic viscosities in m-cresol and weight average molecular weights, M?_w, were measured for samples of high molecular weight poly(2-pyrrolidone) (poly ( 1 )) prepared by anionic polymerization of 2-pyrrolidone ( 1 ) accelerated with CO₂. It was proved that the earlier found relationship [η] = 4 · 10^?2 · M^0,77 (in cm³ · g^?1) holds for M?M_w up to 8 · 10⁵ g. mol^?1. The probable reason for the formation of poly ( 1 ) with an exceptionally high molecular weight is discussed.     

Solvent effect on the propagation rate constant in the radical polymerization of bis(2-ethylhexyl) itaconate

Polymerization of bis(2-ethylhexyl) itaconate ( 1 ) with dimethyl azobis(isobutyrate) ( 2 ) was carried out at 50°C in various solvents. Polar solvents caused a significant decrease in the polymerization rate (R_p) and the molecular weight of resulting poly( 1 ). The propagating poly( 1 ) radical could be observed as a five-line ESR spectrum in the actual polymerization systems used. The stationary concentration of poly( 1 ) radical was determined by ESR to be 4,2–6,4 · 10^?6 mol · L^?1 at 50°C when the concentrations of 1 and 2 were 1,03 and 3,00 · 10^?2 mol · L^?1. Using R_p the monomer concentration and the polymer radical concentration, the propagation rate constant (K_p) was estimated to be 1,4–6,8 L · mol^?1 · s^?1, depending on the solvents used. The k_p value was smaller in more polar solvents. The solvent effect is explained in terms of the solvent affinity for the propagating polymer chain.     

Photo-oxidative degradation and stabilization of isotactic poly(1-butene) in solid state, 1

The kinetics of photo-oxidative degradation and stabilization of poly(1-butene), [poly(1-ethylethylene), PB-1] at 253, 7 nm and a constant intensity of 2,38·10^?9 Einstein.s^?1·cm^?2 (1,12·10^?3 J·mol^?1·s^?1·cm^?2) was studied in the absence and presence of 0,1 wt.-% 6-(2-hydroxyphenyl)-2,4-diphenyl-1,3,5-triazine ( 1 ) dispersed evenly in the matrix of polymer films in the temperature range of 267 to 313 K. The progress of the reaction was followed by measuring the rate of chain scission of the polymer. It has been confirmed by light scattering and potassium ferrioxalate actinometric measurements that random scission of the polymer chain occurs and 1 acts as a stabilizer to the photo-oxidative degradation processes. Irrespective of the variations in the values of ΔH^≠ and ΔS^≠ the values of ΔF^≠ remain almost constant around 159 kJ·mol^?1 indicating that the rate determining step is the same for both systems.