Poly(oxyethylene)s terminated at both ends with phosphonium ion end groups, 1. Synthesis and characterization

The series of poly(oxyethylene)s (poly-EO) with number-average degrees of polymerization ranging from ≈6 to ≈80, terminated at both ends with phosphonium ion groups, was prepared by conversion of hydroxyl end groups of α-hydro-ω-hydroxypoly(oxyethylene)s into bromide end groups, followed by the reaction with triphenylphosphine. The functionality of the products (diionic poly-EO) was determined by elemental analysis, ¹H and ³¹P NMR as well as mass spectroscopy (MS). The observation of the signals corresponding to individual oligomers in ³¹P NMR spectra of short chain (DP_n < 10) diionic poly-EO was explained by intramolecular aggregation of ionic end groups leading to cyclic structures. The measurements of spin lattice relaxation times and the chemical shifts of phosphorus at different conditions (temperature, solvent, concentration) confirmed, that the aggregation of ionic end groups is clearly manifested in the ³¹P NMR spectra of diionic poly-EO.     

Poly(oxyethylene) terminated with tertiary amino or quaternary ammonium groups

α-(3-Dimethylaminopropyl)-ω-dimethylaminomethylpoly(oxyethylene)s (2a–e) were prepared from α-(3-aminopropyl)-ω-aminomethylpoly(oxyethylene)s (1a–e) (M?_n = 430–2300 g·mol^?1), by the Wallach-Leuckart reaction, with a degree of transformation of ? NH₂ into ? N(CH₃)₂ groups of 70–98%. The samples were characterized by means of IR spectrometry and Siggia's acylation method, adjusted for microdetermination. The polymers terminated with 3-dimethylaminopropoxy groups were transformed into the corresponding derivatives bearing quaternary ammonium end groups, and characterized both as dihydroxides and dichlorides. The content of the quaternary ammonium groups was found to differ considerably for the individual samples in the range of 19–97%. The reason for this variability was found not to be a low efficiency of the quaternization reaction, but the Hofmann-degradation giving rise to terminal vinyl groups of the polyether chain.     

Telechelic poly(ε-caprolactone) terminated at both ends with OH groups and its derivatization

The synthesis of highly uniform (1,08 ≤ M _w/M _n ≤ 1,13) telechelic poly(ε-caprolactone) terminated at both ends with OH groups and its derivatization leading to poly(ε-caprolactone) with pyrene end-groups are described. The synthesis, carried out in THF at room temperature, involves initiation with (CH₃CH₂)₂AlO(CH₂CH₂O)₃Al(CH₂CH₃)₂, leading to poly(ε-caprolactone) macromolecules growing at both ends. The active centers were deactivated with acetic acid, giving macromolecules with OH end-groups. Reaction of α,ω-dihydroxypoly(ε-caprolactone), HO-poly(εCL)-OH, with 4-(1-pyrenyl)butyryl chloride yields α,ω-di-1-pyrenylpoly(ε-caprolactone), Py-poly(εCL)-Py. Polymers are characterized by GPC, ¹H NMR, and UV spectroscopies. The UV spectra of polymers with pyrene end-groups are compared with the UV spectra of the model compound.     

Poly(butylene terephthalate) oligomers containing organosilane end groups

Oligomers with poly(butylene terephthalate) (PBT) containing organosilane extremities were prepared by reacting an α-allylic oligomer of PBT with silanethiols or with silanes. The α-allylic oligomer of PBT was synthesized by condensation of allyl alcohol, 1,4-butanediol and terephthaloyl dichloride. All the oligomers were characterized by means of proton nuclear magnetic resonance, Fourier-transform infrared spectroscopy, size-exclusion chromatography, gas chromatography and high-performance liquid chromatography. Their thermal properties were also investigated.     

Synthesis of polymers with primary amino end groups, 2. Synthesis of polyisoprene with primary amino end groups and poly(isoprene-b-γ-benzyl-L-glutamate)s

Primary amine terminated polyisoprene 2 was produced by reaction of anionic living polyisoprene with one of the following protected aminating reagents: N-(benzylidene)trimethylsilylamine ( 1a ). N-(1-phenylpentylidene)trimethylsilylamine ( 1b ), N-benzylidenebenzenesulfeneamide ( 1c ), or N,N-bis(trimethylsilyl)-2-bromoethylamine ( 3 ). Especially with 1a , the terminal amino group was quantitatively introduced at the end of the polymer chain. 2 was found to initiate the polymerization of the N-carboxy anhydride of γ-benzyl-L -glutamate 5 to afford poly(isoprene-b-γ-benzyl-L -glutamate) ( 6 ).     

Poly(ether ketone)s with cyclohexyl-substituted indan groups in the main chain

Poly(ether ketone)s containing 1,3-dicyclohexyl-1-methyl-3-phenylindan groups in the main chain were prepared from different bisphenols and a bisfluoride monomer which contains the indan group. The bisfluoride monomer was synthesized in a three-step process, starting from cyclohexyl phenyl ketone. All polymers are soluble in tetrahydrofuran, chloroform and N,N-dimethylpropyleneurea. No melt transitions were detected by differential scanning calorimetry. Glass transition temperatures are relatively high (218°C to 255°C). In gel-permeation chromatography with polystyrene calibration, 8400 < M?_n < 17900 and 34500 < M?_w < 76600 were found. The thermooxidative stability of these polymers is fairly low with decomposition starting at 400°C in air. This was attributed to the methine group of the cyclohexyl ring since the major decomposition products proved to be cyclohexane and cyclohexene.     

Poly(amido-amine)s and poly(ester-amine)s based on aromatic amines containing carboxyl groups

The preparation of poly(amido-amine)s and poly(ester-amine)s via polyaddition between aromatic amines containing free or esterified carboxyl groups and compounds with activated double bounds [N,N′-methylenebis(acrylamide), 1,4-diacryloylpiperazine and 1,3-propanediyl diacrylate] is described. The products obtained are typical polyelectrolytes, their solutions exhibiting anomalous viscosity behaviour.     

Mobile Macromolecular Carriers of Ionic Substances, 2. Transport Rates and Separation of Some Divalent Cations by Poly(oxyethylene) Phosphates

The permeation of Cu(II), Zn(II), Mn(II), Co(II), Ni(II) as facilitated by soluble macromolecular carriers (macroionophores) was investigated in a multimembrane hybrid system (MHS). The system was composed of two cation‐exchange polymer membranes and an agitated bulk liquid membrane containing one of the following polymers as the transport activating component: ω‐methoxy‐poly(oxyethylene) phosphate (MPOEP, 1 ), α,ω‐poly(oxyethylene) bisphosphate (POEBP, 2 ), and α,ω‐poly(oxyethylene) bis(dimethyl phosphate) (POEBMP, 3 ) of various molecular mass. For comparative studies, poly(ethylene glycol)s (PEG, 4 ) of equivalent molecular mass (1 500–6 000), were also studied. The results have been analysed by comparing the overall metal cation fluxes, facilitation factors, and separation coefficients. It was found that compound 2 exhibits favourable carrier properties represented by the ionic fluxes as high as 2·10^–11 mol/(cm²·s). This macromolecular carrier allows the achievement of transport facilitation factors ranging from 10 to 100 with respect to the system without any carrier, and from 6 to 34 with respect to the system containing an equivalent amount of PEG. The specific values depend on molecular mass of POE in 2 , with a maximum at POE 2000. The mechanism of transport when mediated by the ionic macromolecular carriers 1 and 2 is probably influenced by their bifunctional character involving the cooperation between ion exchange processes and ion binding by pseudocyclic structures of poly(oxyethylene) moieties.     

Stereoregularity of polystyrene derivatives, 2. Poly(methoxystyrene)s Obtained by Anionic Catalysts.

The stereoregularity of poly(methoxystyrene)s was determined from the absorption of the aromatic C¹ carbon assuming a first-order Markov statistics holds for the polymerization as well as polystyrenes. The stereoregularity of poly(p-methoxystyrene)s prepared by sodium, potassium, or rubidium cations as catalysts in THF hardly varied and syndiotactic-rich polymers were obtained, whereas a random polymer was formed with cesium-naphthalene. In the polymerization of p-methoxystyrene in toluene, syndiotactic-rich polymers were obtained with butyllithium and random polymers were prepared by sodium or potassium cations as catalysts. The stereoregularity of poly(o-methoxystyrene)s prepared by sodium or potassium cations in tetrahydrofuran changed with the polymerization temperatures, and highly syndiotactic polymers were formed at?78°C. The structure of poly(o-methoxystyrene)s obtained in toluene, markedly depended on the initiators; that is, with increasing the size of the ionic radius of the counterions, the isotacticity of the polymers decreased. The mechanism of the polymerization and the substituent effect of the stereoregularity are discussed.     

Synthesis and Properties of Novel Cardo Aromatic Poly(ether oxadiazole)s and Poly(ether‐amide oxadiazole)s

A series of polyhydrazides and poly(amide hydrazide)s bearing ether and cardo groups were prepared from three bis(ether carboxylic acid)s, 1,1‐bis[4‐(4‐carboxyphenoxy)phenyl]cyclohexane, 5,5‐bis[4‐(4‐carboxyphenoxy)phenyl]‐4,7‐methanohexahydroindan and 9,9‐bis[4‐(4‐carboxyphenoxy)phenyl]fluorene, or their diacyl chlorides with terephthalic dihydrazide, isophthalic dihydrazide and p‐aminobenzoyl hydrazide via the phosphorylation reaction or the low‐temperature solution polycondensation. The resulting hydrazide‐containing polymers exhibited inherent viscosities in the range of 0.35–0.71 dL·g^–1. All the hydrazide polymers were found to be amorphous as determined by X‐ray diffraction analysis and soluble in many organic polar solvents, and most of them afforded flexible and tough films by solvent casting. The hydrazide polymers had glass transition temperatures (T_g) between 157 and 197°C. All hydrazide polymers could be thermally converted into the corresponding oxadiazole polymers approximately in the region of 270–370°C, as evidenced by the DSC thermograms. The oxadiazole polymers showed a slightly enhanced crystallinity and an increase of T_g and a dramatically decreased solubility compared to their hydrazide prepolymers. They exhibited T_g's of 218–259°C and showed insignificant weight loss up to 450°C.     

Synthesis and Spectral Properties of Novel Poly(disubstituted acetylene)s

The synthesis of mostly new acetylenes, R₁C?CR₂, (R₁ = 4‐t‐butylphenyl; R₂ = 4‐t‐butylphenyl; 4‐[(t‐butyl)(diphenyl)silyloxy]phenyl; 1‐naphthyl; 2‐naphthyl; 9‐anthryl) is reported. Their UV‐vis characteristics are discussed in comparison to the results of TD‐DFT calculations. R₁C?CR₂ (except for R₂ = 9‐anthryl) give polyacetylenic polymers—[C(R₁) = C(R₂)]‐_n, insoluble if R₁ = R₂ and well soluble if R₁ ≠ R₂ in polymerization with TaCl₅/SnBu₄. Polymerizability increases with increasing monomer triple bond accessibility for the catalyst. The photoluminescence yield of the soluble polymers rises in the R₂ order: 1‐naphthyl < 2‐naphthyl < 4‐[(t‐butyl)(diphenyl)silyloxy]phenyl.

     

Telechelics, 7. Polytetrahydrofuran with acetate end groups

Tetrahydrofuran (THF) was polymerized by protic and non-protic cationic initiators in presence of acetic anhydride (Ac₂O) in methylene dichloride. Due to a low transfer coefficient (C_Ac2o = 0,058) the molecular weight increases during the early part of the reaction. The consumption of Ac₂O continues even when the THF concentration approaches zero, which results in a lowering of the number-average degree of polymerization P_n. Degradation of poly(THF) continues until the Ac₂O is exhausted. The equilibrium concentration of THF can reach almost zero at small P_n. The equilibrium constants K₂, K₃, K₄, etc., up to K₂₃ for the successive monomer additions are obtained from gel permeation chromatography. With the exception of K₂ the equilibrium constants K_n are independent of n.     

Quasi-living surface graft polymerization with phosphorylcholine group(s) at the terminal end

A surface graft polymer with one or two phosphorylcholine (PC) polarheads at the terminus of the growing chain end was prepared by sequential reactions on a glass substrate. The dithiocarbamate group covalently bound to glass surfaces was derivatized with one or two PC groups and then irradiated with ultraviolet light in the presence of N,N-dimethylacrylamide (DMAAm). X-ray photoelectron spectroscopy, wettability measurements and dye staining experiment for the PC group showed that the resultant graft copolymers were produced via iniferter-based quasi-living radical polymerization, in which the polyDMAAm graft chain contains one or two PC groups at the terminal end of the graft chain. These polymer surface grafts may help provide biocompatibility.     

Poly(phenylacetylene)s Carrying Siloxy,Carbonate, and Hydroxy Groups: Synthesis and Properties

t‐Butyldimethylsilyl (t‐BDMS) and t‐butoxycarbonyl (t‐Boc) protected 3‐ and 4‐hydroxyphenylacetylene monomers were synthesized and polymerized using [(nbd)RhCl]₂ ( 1 ) and [(nbd)RhBPh₄] ( 2 ) catalysts. The t‐BDMS‐containing polymers [poly( 3a ) and poly( 4a )] were obtained in good yield (45–69%) while the t‐Boc‐protected monomers polymerized in a high yield [poly( 5a ) and poly( 6a ): 80–100%]. The use of KN(SiMe₃)₂ as a cocatalyst in conjunction with 1 led to a dramatic increase in the molecular weight of the polymers. The acid‐catalyzed removal of the t‐BDMS group afforded the naked hydroxy‐containing polymers [poly( 3b ) and poly( 4b )] which cannot be obtained directly by the polymerization of the corresponding monomers. The polymers containing protected ? OH moieties were more soluble in less polar solvents, whereas their deprotected counterparts displayed good solubility in polar protic or highly polar aprotic solvents. The attempts to accomplish the free‐standing membrane fabrication by solution casting were successful only for poly( 3a ) and an augmentation in the gas permeability was discerned in comparison with the unsubstituted poly(phenylacetylene) and poly(o‐methylphenylacetylene).

     

Preparation of poly(amide-imide)s by direct polycondensation with triphenyl phosphite, 3. Poly(amide-imide)s based on bis(trimellitimide)s

Six dicarboxylic acids ( 1a–f ) were prepared from trimellitic anhydride and 4,4′-oxydianiline, 4,4′-methylenedianiline, 4,4′-sulfonyldianiline, benzidine, 1,6-hexamethylenediamine, and 4,4′-methylenedicyclohexylamine. These diacids were condensed directly with various aromatic diamines using triphenyl phosphite in 1-methyl-2-pyrrolidone/pyridine solution in the presence of calcium chloride. The inherent viscosity of the polymers is affected by the nature of the diamine and the solubility of the resulting polymers in the reaction media. The highest η_inh-value of a poly(amide-imide) obtained was 1,41 dl/g (in N,N-dimethylacetamide/5% LiCl at 30°C). Among the polymers, the wholly aromatic ones show better solubility, higher glass transition temperatures, and higher thermostability than the aliphatic-aromatic ones. Well-defined melting points (T_m) of most wholly aromatic poly(amide-imide)s were not obtained by differential scanning calorimetry (DSC); however, some poly(amide-imide)s containing aliphatic chains showed clear T_m in the first DSC heating traces. Measurements of wide-angle X-ray diffraction revealed that those polymers containing biphenyl or linear hexamethylene groups are partially crystalline. Flexible films with excellent tensile properties were cast from N,N-dimethylacetamide solutions of most of the wholly aromatic poly(amide-imide)s.     

Poly(ether-sulfone)s with indan structure elements

Various poly(ether-sulfone)s with 1,1,3-trimethylindan units along the main chain were synthesized from different diphenols and activated dihalogen monomers containing the 1,1,3-trimethylindan moiety. The indan-containing monomers were derived from 1,1,3-trimethyl-3-phenylindan by sulfonylation with 4-halobenzenesulfonyl chloride in the presence of the Friedel-Crafts catalysts. The polymers are amorphous with glass transition temperatures between 206 and 247°C, and decomposition temperatures above 460°C in air. Due to their solubility in common organic solvents such as tetrahydrofuran and chloroform, the polymers could be fully characterized by gel-permeation chromatography as well as ¹H- and ¹³C NMR spectroscopy.     

Poly(ether-ketone)s with indan structure elements

1,1,3-Trimethyl-3-[4-(4-fluorobenzoyl)phenyl]-6-(4-fluorobenzoyl)indan ( 5a ) and the isomer 5b were synthesized by Friedel-Crafts acylation of 1,1,3-trimethyl-3-phenylindan with 4-fluorobenzoyl chloride. This reaction yields a mixture of two isomer. The pure isomer as well as the isomer mixture were employed in the synthesis of poly(ether-ketone)s via nucleophilic displacement of activated aromatic halogens by different diphenols. The influence of the indan structure element on the polymer properties such as glass transition temperature, crystallinity, solubility, and thermal stability was investigated.     

Long-term change in conformation of macromolecules in solution, 2. Poly(acrylamide-co-sodium acrylate)s

The solution viscosity of aqueous poly(acrylamide-co-sodiumacrylate)s decreases with time in the scale of weeks. This unusual viscosity loss has been investigated by viscometry and by light scattering on high purity copolymer samples with different ratios of the components. — No viscosity loss can be observed in NaCl solution of high enough salt concentration. From the experiments it is concluded that a conformational change causes the viscosity decrease. No chain scission occurs. Light scattering measurements were used to directly confirm this hypothesis. — The viscosity loss may be caused by a conformational change of single molecules involving hydrogen bonds and can be interpreted as a transition from a partly stiffer, higher viscous structure to a more flexible one. As the driving force for the conformational change the entropy is discussed. The pronounced time dependence may be interpreted by a cooperative effect of loosening and combining of hydrogen bonds. — A similar behaviour has been observed earlier in aqueous poly(acrylamide) solutions. Thus, for some water soluble polymers one has to be aware of a time dependent parameter.