RAFT synthesis of acrylic polymers containing diol or dioxane groups

In this paper, the morphology of thermotropic systems with fixed domains (TSFD) was evaluated applying high resolution Atomic Force Microscopy (AFM) also upon heating and cooling. Furthermore nano-mechanical characteristics of the samples were determined by means of Force/Distance spectrometry. TSFD formulated with additive types exhibiting a short chain length displayed roughly spherical scattering particles with dimensions between 0.6???m and 4???m. By means of Force Distance spectroscopy stiffness values of 0.6?N/m and 7.8?N/m were determined for the scattering domains and the matrix, respectively. Upon heating, melting and deliquescence of the additive along with migration was ascertained. After cooling to ambient temperature the formation and growth of terrace-like additive domains on the surface was recorded. Additive types with long-chain molecules developed anisotropic scattering domains resembling distorted disks without predominating orientation. Diameters up to 50???m and a thickness between 200?nm and 600?nm were ascertained. Determination of stiffness yielded values of 0.9?N/m and 13.1?N/m of the scattering domains and the matrix, respectively. Upon heating, swelling and deliquescence of the additive were detected. After cooling to ambient temperature a partial recovery of swelling was observed. Force-Distance spectroscopy yielded a 5 to 10?nm thick additive layer which coated wide areas of the surface after the heating cycle for all samples investigated.     

Chemical synthesis of some Schiff base-type polymers containing pyrrole units

Summary The synthesis of three Schiff-base type monomers containing pyrrole units was performed. Their polymerization was carried out by chemical oxidation with (NH₄)₂S₂O₈. Some preliminary thermal and electrical properties were determined.     

Redox polymers containing p-phenylenediamine groups

Oxidation-reduction reactions and some applications of polymers containing p-phenylenediamine skeleton in side branches were studied in aqueous solutions. The polymer was used also for preparation of immobilized enzymes by oxidative coupling reaction. The materials were prepared under biologically tolerable conditions and exhibited fairly high biological activity.     

Reactive monomers and polymers containing chiral groups

N-(p-methylstyryl)-(1R,2S)-ephedrine is prepared by alkylation of p-chloromethylstyrene under conditions which do not favor quaternization. A series of Copolymerization reactions confirm that the new chiral monomer and styrene copolymerize in random fashion with r₁=1.09 and r₂=0.98. The optical rotation of the copolymers does not vary linearly with composition. Applications of the copolymer include its use as chiral ligand for asymmetric synthesis or as a separation medium.     

Novel luminescent polymers containing backbone triphenylamine groups and pendant quinoxaline groups

Novel, conjugated polyfluorene derivatives that comprised an electron-donating triphenylamine group in the backbone and pendant, electron-accepting quinoxaline moieties, were synthesized via the Suzuki coupling reaction and their UV–vis absorption, fluorescence emission and electrochemical properties were investigated. The copolymers were readily soluble in common organic solvents and displayed good film-forming ability and excellent thermal stability. Electroluminescence devices, comprising indium tin oxide/poly(3,4-ethylenedioxythiophene) doped with poly(styrenesulfonic acid)/emitting polymer/Ba/Al, in which the polymers were employed as emissive layers, exhibited superior performance compared to that of corresponding, poly(9,9-dioctylfluorene) and poly(9,9-dioctylfluorene-co-4,4′-triphenylamine) based devices, indicating that the polymers offer promise as emissive materials in polymeric light-emitting diodes.     

Synthesis of potentially piezoelectric polymers containing tetracyanocyclobutyl side groups

Three new monomers containing the tetracyanocyclobutyl substituents were synthesized: p-(tetracyanocyclobutyl) styrene 1, p-(1′-methyl-2′,2′,3′,3′-tetracyanocyclobutyl)-α-methylstyrene 2 and [p-(tetracyanocyclobutyl)phenyl] acrylate 3, with the aim of obtaining potentially piezoelectric polymers which contain substituents with high dipole moments. Moderate molecular weight polymers were obtained from monomer 1 only, 2 and 3 did not polymerize. The inhibiting effect of the tetracyanocyclobutyl group was responsible for the molecular weights as demonstrated by model experiments.     

Metal catalyzed photocrosslinking of polymers containing pendant propargyl groups

Polymers containing the pendant propargyl groups can be effectively crosslinked upon UV irradiation in the presence of a small amount of W(CO)₆. The alkyne-tungsten carbonyl complex was formed initially as evident by IR spectroscopy, which was involved in the subsequent crosslinking reaction. Analyses by UV, IR, and ¹³C NMR CP/MAS spectroscopic methods confirmed the polymer crosslinking as a result of the conversion of the acetylenic units to the polyene and diacetylene moieties in the crosslinked system.     

Optically active vinyl polymers containing fluorescent groups. 6

Summary Copolymers of carbazole-containing monomers such as 4- and 3-(9-carbazolylmethyl)styrene (1 and 2), 2(9-carbazolyl)ethyl methacrylate (3) and 2-(9-carbazolylacetyloxy)ethyl methacrylate (4) with optically active menthyl acrylate (5) and methacrylate (6) were prepared by free radical polymerization.In all cases optically active copolymers were obtained and for copolymer samples of 1 and 2 with 5 and 6, CD spectra indicate an appreciable, even if small, dissymmetric perturbation of heteroaromatic moiety.NMR and fluorescence emission spectra of the above copolymers are consistent with a monomer-type behaviour which can be associated with a high dishomogeneity of the conformational environment in which the aromatic chromophores are located.Profiles of the UV band in the 230–240nm region are analysed in terms of the different structural features of the copolymers. ¹H-NMR spectra recorded on partially deuterated po1y(1) eliminate any contribution by the carbazolyl protons to the upfield signal (6.5–5.5ppm) of the complex aromatic protons resonance.Dedicated to Prof. C.I. Simionescu on the occasion of the 60th anniversary of his birthday     

Synthesis and exchange reactions of polymers containing reactive phthalimide groups

N-Methacryloyloxyphthalimide (NMPI) and N-methacryloyloxytetrabromophthalimide (NMTPI) were prepared by the reaction of methacrylic acid with N-hydroxy-phthalimide and N-hydroxytetrabromophthalimide, respectively. The resulting monomers were polymerized. The reactions of the resulting polymers with hydroxy and amine compounds have been studied.     

Chemical transformations of polymers,XXI. Imidazole containing polymers from crosslinked macroporous poly(methacrylic acid esters) with reactive sulfoester groups

New imidazole containing polymers were synthesized by nucleophilic substitution reactions of poly(ethylene methacrylate arylsulfonates) with imidazole, benzimidazole and some of their derivatives. The reaction time and the solvents used had varying effects on the binding rates. The conversion was best reproducible at high reaction speed in ethanol.     

Synthesis and characterization of fluorene-based electroluminescent polymers containing silyl groups

Summary Two types of fluorene-based copolymers, poly(9,9'-di-n-hexyl-2,7-fluorenediyl-ethynylene-alt-9-trimethylsilyl-2,7-fluoreneethynylene[P-1], poly(9,9-di-n-hexyl-2,7-fluorenediylethynylene-alt-9,9'-bis-trimethylsilyl-2,7-fluoreneethynylene[P-2] were synthesized by employing palladium catalyzed polycondensation. Resulting polymers showed a good solubility in various organic solvents such as THF, chloroform, dioxane etc. and could be easily spin-coated onto an ITO glass plate to make a fine thin film. Characterization of these polymers includes FT-IR, UV-vis., ¹H and ¹³C-NMR, was conducted. Thermal properties were also investigated by DSC and TGA as well as molecular weight studies. The present polymers exhibited emission of blue-white color. The photoluminescence (PL) spectrum of the polymers showed two peaks at 490 and 540 nm and it was found that electroluminescence (EL) spectra of the polymer [P-2] was very similar to its PL spectrum. Received: 17 September 2001/ Accepted: 12 October 2001     

Preparation and study of functionalized polymers containing pendent pesticide-active groups

A number of pesticide monomers containing pentachlorophenol as active group attached to vinyl groups, through oxyethylene as spacer group, have been prepared. The resulting monomers were homopolymerized under free-radical conditions and also copolymerized with styrene and 2-(2-hydroxyethoxy)ethyl methacrylate to introduce hydrophobic and hydrophilic nature to the resulting polymers. In addition, crosslinked copolymers were prepared by using different ratios of divinylbenzene. Data on the pentachlorophenol released through hydrolysis show that the degree of crosslinking, the hydrophilicity and the spacer group, as determined by the chemical structure and the polymer composition, as well as the pH, time and temperature appear to be major factors governing the rate at which a given polymer undergoes hydrolysis.     

Template synthesis of mesoporous silicas containing phosphonic groups

Mesoporous silicas containing the functional group ≡Si(CH₂)₂P(O)(OC₂H₅)₂ in the surface layer have been obtained using the template method (template—P123). Their treatment by a concentrated hydrochloric acid results in the formation of functional groups of the composition ≡Si(CH₂)₂P(O)(OH)₂ that is in agreement with the IR spectroscopy data. It has been shown that the above treatment causes an increase of the sample specific surface area (up to 605 m²/g), sorption capacity, and pore diameter. As established by means of the CP/MAS NMR spectroscopy on ³¹P nuclei, the sample drying in vacuum at 110°C results in the formation of fragments ≡Si(CH₂)₂P(O)(OH)—OSi≡ with the content of 10–15 wt %. However, according to the TEM data, the sample mesoporous structure is retained.     

Properties of blends of starch and synthetic polymers containing anhydride groups

Corn starch was blended with styrene maleic anhydride copolymer (SMA), ethylene-propylene-g-maleic anhydride copolymer (EPMA), and corresponding nonfunctional polystyrene and ethylene propylene copolymers. The concentration of starch in the blend was varied between 50 and 80% by weight. The torque generated during blending is reported increasing starch content for starch/SMA blends: the reverse was true for starch/EPMA blends. The torque was higher for the blends of the anhydride functional polymers compared to the blends of corresponding nonfunctional polymers. Water absorption of the blends increased with an increase in the starch content. Starch/SMA blends made at higher mixer speed or time were more water sensitive. Blends containing EPMA absorbed less water than SMA blends containing the same weight fraction of starch. Tensile strengths of blends containing functional groups were superior compared to the blends made from nonfunctional polymers. When the starch contents increased from 60 to 70%, the tensile strength remained unchanged for SMA blend but increased for EPMA blend. All samples supported the growth of microorganisms, which increased with increasing starch content. © 1994 John Wiley & Sons, Inc.     

π-Stacking of rhodamine B onto water-soluble polymers containing aromatic groups

Evidences of the π-stacking of rhodamine B onto poly(sodium 4-styrenesulfonate) are given by ¹H NMR spectroscopy. As a consequence of these π-π interactions, changes on the diafiltration and UV-vis absorbance and fluorescence patterns are shown comparing water-soluble polymers containing aromatic rings as poly(sodium 4-styrenesulfonate) and poly(N-methacryloyl-5-aminosalicylic acid) with other polyanions that do not contain aromatic rings as poly(sodium vinylsulfonate) and poly(acrylic acid).     

Synthesis and catalytic activity of optically active polymers containing oxime groups

Optically active polymers containing oxime groups have been prepared: (i) by partial quaternization of poly(4-vinyl pyridine) (P4VP) with phenacyloxime bromide and with (+)-(S)-1-bromo-2-methylbutane; and (ii) by reaction of the copolymer from 4VP and (+)-(S)-5-methyl-1-hepten-3-one with hydroxylamine. These polymers have been used as catalysts for the esterolysis of esters of p-nitrophenol with non-chiral and with chiral acids. The kinetic parameters of the catalytic process are markedly dependent on the structure of polymer and substrate. A moderate chiral discrimination of the antipodes of p-nitrophenyl 2-methylbutanoate is observed with the catalyst obtained from the copolymer of 4VP with (+)-(S)-5-methyl-1-hepten-3-one.     

Synthesis,characterization and thermal behaviors of polymers containing organosilicon groups

Various bis(silyl)ethenyl groups were attached to the aromatic ring of poly(α-methylstyrene) via Peterson olefination reaction of (RMe₂Si)₃CLi (R = H, Me and Ph) with formylated poly(α-methylstyrene) (Pα-MS-CHO) to give poly(α-methylstyrene)-co-[2,2-bis(silyl)ethenyl(α-methylstyrene)] as functionalized poly(α-methylstyrene) (Pα-MS-SiMe₂H, Pα-MS-SiMe₃ and Pα-MS-SiMe₂Ph). The trimethylsilyl groups of Pα-MS-SiMe₃ have been converted to 2,2-dibromoethenyl and epoxybis(silanes) groups via NBS-based bromodesilylation and MCPBA-based epoxidation respectively. The thermal degradation behaviors of the polymers were studied using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC).     

Functional monomers and polymers, 98. Asymmetric induction by chiral polymers containing bornyl groups

In order to determine the catalytic ability of the polymers containing chiral bornyl groups to the asymmetric induction, the asymmetric addition reaction of dodecanethiol to isopropenyl methyl ketone was studied using synthetic chiral polymers having pendant bornyl groups, in comparison with the case of using a monomeric model compound, i.e. d-bornyl acetate, and also poly(methyl methacrylate). It was found that the polymers having chiral borynl groups were effective for the asymmetric induction, and the optical yield depended on the bornyl group content in the polymers.     

Chemical modification of polymers. II. Attachment of carboxylic acid containing molecules to polymers

The attachment of a molecule bearing an acid function to a macromolecular chain can be afforded by various types of linkages. Many of these are easily accessible and some can be reversible links. The ester linkage is specially well developed with hydroxylated polymers or non-hydroxylated polymers (especially epoxidized polymers) used as supports. Special attention is paid to the glycidyl group (= 2,3-epoxypropyl) which has been introduced to various polymers, providing species with pendent expoxy arms. The catalysis, stereochemistry, secondary reactions, methods of evaluation of the epoxide content, spectroscopic characterization and the mechanism of the addition of acids to epoxides are reviewed.     

Novel synthesis of phosphorus containing polymers under inverse phase transfer catalysis

A novel synthesis of polyphosphates by inverse phase transfer catalysis (IPTC) was investigated. The reaction of methylphosphoric dichloride (MPD) and sodium salt of bisphenol A (BA) in two-phase H₂O/CH₂Cl₂ medium under IPTC is presented and the results are evaluated by the yield and inherent viscosity values. The biphasic medium does not require rigorous stirring. The polyphosphate was characterized by IR, ¹H NMR, ³¹P NMR, inherent viscosity, thermal analysis, and molar mass. Pyridine (Py), pyridine-oxide (PNO) and 4-dimethylamino-pyridine (DMAP) were used as the inverse phase transfer catalysts. DMAP was found to be the best catalyst.