Polymerization Behaviour of Organically Modified Titanium Alkoxides in Solution

Modified titanium alkoxides with polymerizable organic ligands allow the synthesis of copolymers consisting of hybrid organic/inorganic networks. In this work titanium based-precursors were characterized in relation to the polymerization behaviour of the organic matrix. Alkoxide sols were prepared by reaction of methacrylic acid, itaconic acid anhydride, isoeugenol, p-vinylbezoic acid, p-vinylphenylacetic acid, and acetoxyacetomethacrylate with titanium tetraisopropoxide and titanium tetraethoxide. Polymerization reactions were carried out in solution using UV-irradiation and a redox-system of dibenzoylperoxide/N, N-dimethyl-p-toluidine as radical initiators. Especially for chemical activation some complexes showed high reactivity similar to silica-based methacrylates. The systems investigated are capable of acting as adhesive promoters between metal and polymer in dental applications.     

COMPATIBILIZATION OF POLY(ETHYLENE OXIDE)/POLY(STYRENE) BLENDS: EFFECT OF THE MOLECULAR WEIGHT OF THE COMPATIBILIZER

The effect of the molecular weight and concentration of the compatibilizer maleic acid-alt-styrene copolymer (MAaS) on the compatibility behavior of incompatible poly(ethylene oxide)/poly(styrene) (PEO/PS) blends was studied by differential scanning calorimetry (DSC) and polarized light microscopy (PLM). PEO with [Mbar] _w = 100,000 (PEO₁₀₀) and PS with [Mbar] _w = 225,000 (PS₂₂₅) were used for this study. DSC measurements showed two T _g values that were shifted relative to those of the pure components. This result should be indicative that MAaS acts as a compatibilizer for the blend. Diminishing of the spherulitic growth rate G was observed as the content and molecular weight of MAaS increased in the blend. This result was confirmed by morphological analysis, by which it was possible to observe that the amorphous component diminished its droplike domains. Contact angle measurements suggest that the wettability of PEO drops on a PS/MAaS surface are larger in the system containing MAaS as the compatibilizer.     

正交实验法研究MAH-β-CD衍生物的制备工艺

用顺丁烯二酸酐（MAH）对β-环糊精（β-CD）进行化学改性,合成出了顺丁烯二酸酐-β-环糊精衍生物（MAH-β-CD）。针对影响衍生物制备的因素,采用正交实验法,以产物产率为评价指标,优选顺丁烯二酸酐-β-环糊精衍生物制备的最佳工艺条件为：投料比1∶10,反应温度80℃,反应时间9h。     

Preliminary study of extractable protein binding using maleic anhydride copolymer

A preliminary study of using maleic anhydride copolymer for protein binding has been carried out.The polymeric films were prepared by compression of the purified resin and annealing the film to induce efficient back formation of the anhydride groups.The properties of the film surface were analyzed by attenuated total reflection Fourier transforms infrared spectroscopy and water contact angle measurements.The protein content was determined by Bradford assay.To obtain optimum conditions,immersion time for protein binding was examined.Results revealed that proteins can be successfully immobilized onto the film surface via covalent linkage.The efficiency of the covalent binding of the extractable protein to maleic anhydride-polyethylene film was estimated at 69.87μg/cm~2,although the film had low anhydride content(3%) on the surface.     

Diphenylarsinoderivate des Maleinsäureanhydrids und verwandte Verbindungen. Kristall- und Molekülstruktur des 2,3-Bis(diphenylstibino)maleinsäureanhydrids

The unusual properties of bis(diphenylphosphino)maleic anhydride and similar ditertiary phosphines has prompted the synthesis of analogous arsines and stibines. Bis(diphenylarsino)maleic anhydride,-maleic thioanhydride and-N-methyl maleic imide, bis(diphenylstibino)maleic anhydride (5) and-maleic thioanhydride are obtained as crystalline yellow or red compounds by the reaction of the corresponding 2,3-dichloromaleic acid derivatives with diphenyl(trimethylsilyl)arsine and-stibine resp. The uv/vis spectra and characteristic i.r. bands of selected compounds are given and compared with those of the corresponding phosphines. The strong shift of _C=C to lower wavenumbers observed in all compounds has caused the determination of crystal and molecular structure of5 by x-ray diffraction. Bond distances and angles are given. The complex formation of the new diarsine ligands has been examined by the preparation of Ni-, Cr- and Mo-carbonyl derivatives. As the first organylsulfane substituted maleic acid derivatives bis(phenylthio)maleic thioanhydride,-N-methyl-maleic imide and-maleic acid dimethylester are synthesized and described.

     

Production of polymer microparticles by “dissolution” of submicron-sized water-insoluble ionized carboxylated polymer particles in the presence of various nonionic emulsifiers

Styrene-butyl acrylate-methacrylic acid terpolymer (50.4/40.9/8.7, molar ratio) particles, 276 nm in diameter, were produced by emulsifier-free emulsion terpolymerization. The emulsifier-free carboxylated terpolymer particles did not dissolve in water even under alkaline condition. However, they dissolved in the presence of nonionic emulsifier under alkaline condition, resulting in polymer microparticles having diameter less than 40 nm. Such a dissolution behavior was examined using five kinds of different polyoxyethylene nonylphenylether nonionic emulsifiers having hydrophilic-lipophilic balance values between 12.2 and 17.5 at various initial pH values, temperatures and times, and its mechanism was discussed.Part CXLIV of the series Studies on Suspension and Emulsion.     

The dissolution of ionized water-insoluble carboxylated polymer particles in the nonionic emulsifier solution

It was found that 276 nm-sized styrene-butyl acrylate-methacrylic acid terpolymer (P(S-BA-MAA)) (50.4/40.9/8.7, molar ratio) particles produced by emulsifier-free emulsion polymerization dissolved in a polyoxyethylene nonylphenylether nonionic emulsifier aqueous solution at pH values above 11 and above 25°C resulted in polymer microemulsion. The weight-average diameter of P(S-BA-MAA) microparticles in the solution was 31 nm, which was measured by dynamic light scattering spectroscopy. Such a dissolution of the particles was not observed in the absence of the emulsifier.Part CXLI of the series Studies on Suspension and Emulsion.     

Surface modification of fine colloidal silica with copolymer silane-coupling agents composed of maleic anhydride

The reactivity of copolymer silane composed of maleic anhydride in the modification of fine colloidal silica was studied. The reaction of colloidal silica of 10 and 45-nm diameter with trimethoxysilyl-terminated poly(maleic anhydride-co-styrene) [P(MA-ST)] and poly(MA-co-methyl methacrylate) in tetrahydrofuran resulted in effective surface modification without particle aggregation. From the results that the reaction using the polystyrene silane of low molecular weight led to partial aggregation, it was suggested that the steric interaction between relatively rigid copolymer chains having a maleic anhydride moiety adsorbed on the silica prevented the aggregation in the reaction. The ²⁹Si cross-polarization magic-angle-spinning NMR spectra of P(MA-ST)-modified silica showed that the polymer silane was bound to the silica surface by the direct reaction with silica hydroxyl groups and via the polymerization. Received: 27 June 2001 Accepted: 6 September 2001     

Radiation grafting of styrene and maleic anhydride onto PTFE membranes and sequent sulfonation for applications of vanadium redox battery

Using γ-radiation technique, poly(tetrafluoroethylene) (PTFE) membrane was grafted with styrene (St) (PTFE-graft-PS) or binary monomers of St and maleic anhydride (MAn) (PTFE-graft-PS-co-PMAn), respectively. Then grafted membranes were further sulfonated with chlorosulfonic acid into ion-exchange membranes (denoted as PTFE-graft-PSSA and PTFE-graft-PSSA-co-PMAc, respectively) for application of vanadium redox battery (VRB). Micro-FTIR analysis indicated that PTFE was successfully grafted and sulfonated at the above two different conditions. However, a higher degree of grafting (DOG) was obtained in St/MAn binary system at the same dose due to a synergistic effect. Comparing with PTFE-graft-PSSA, PTFE-graft-PSSA-co-PMAc membrane showed higher water uptake and ion-exchange capacity (IEC) and lower area resistance (AR) at the same DOG. In addition, PTFE-graft-PSSA-co-PMAc with 6% DOG also showed a higher IEC and higher conductivity compared to Nafion membrane. Radiation grafting of PTFE in St/MAn binary system and sequent sulfonation is an appropriate method for preparing ion-exchange membrane of VRB.