Immobilization of trichordema reesei by radiation polymerization

Immobilization of trichordema Reesei (QM9414) was prepared by radiation polymerization. It was found that the activity of fixed cells increased with inseasing surface area of the carrier and was affected by the concentration of monomer tetraethylenglycol dimethacrylate (4G) and the shape of the substrate composition and structure of cotton textile fabics.     

Immobilization of antibodies and enzyme-labeled antibodies by radiation polymerization

Immobilization of antibodies and enzyme-labeled antibodies by radiation polymerization at low temperatures was studied. The antibody activity of antibody was not affected by irradiation at an irradiation dose of below 8 MR and low temperatures. Immobilization of peroxidase-labeled anti-rabbit IgG goat IgG, anti-peroxidase, peroxidase, and anti-alpha-fetoprotein was carried out with hydrophilic and hydrophobic monomers. The activity of the immobilized enzyme-labeled antibody membranes varied with the thickness of the membranes and increased with decreasing membrane thickness. The activity of the immobilized antibody particles was varied by particle size. Immobilized anti-alpha-fetoprotein particles and membranes can be used for the assay of alpha-fetoprotein by the antigen-antibody reaction, such as a solid-phase sandwich method with high sensitivity.     

Extractive-scintillating resin produced by radiation polymerization

The characterization of a resin material is presented, which contains selective complexing and scintillating molecules in chemically bound form. The resin material is produced via radiation polymerization of the solution of 2-(4-allyloxy-phenyl)-5-phenyl oxazole, 5-(allyloxy-phenyl)-2-[4-(5-phenyl-oxazole-2-il)-phenyl] oxazole, diethylene glycol dimethacrylate (DEGMA), styrene and the allyl derivative of a 18C6 crown ether-dicarbolic acid complexing agent. The product is a macroporous polymer matrix, which shows both excellent scintillation properties and ion binding capacity for radioanalytical purposes.     

Vinyl acetate polymerization by ionizing radiation

For this work an irradiation system to be used in the polymerization of the vinyl acetate in methylethylketone and in ethyl alcohol solution using the gamma radiation as initiator was projected and built. The molecular weights of the polymers obtained by irradiation with gamma rays in methylethylketone and in ethyl alcohol solution were 33,000 and 44,000 g/mol, respectively. From the characterization by infrared spectroscopy it was possible to verify that the polymers obtained in two studied cases actually correspond to poly(vinyl acetate).     

Topotactic solid-state polymerization of 3-aminocrotonamide by radiation

Radiation-induced solid-state polymerization of 3-aminocrotonamide (3-amino-2-butenamide) was carried out at room temperature, in open air atmosphere and under vacuum condition. The polymer obtained was white powder, soluble in methanol, but insoluble in water. The nature of polymers were investigated by IR, UV, x-ray, DP-MS, and elemental analysis to elucidate the mechanism of the polymerization. The polymer was crystalline with melting point in the range of 245–255°C. The cell parameters and space group of monomer and polymers were determined from powder x-ray diffraction patterns. The similarity of crystal structures of monomer and polymer indicated a topotactic polymerization. It was shown by spectroscopic investigations and elemental analyses that the polymerization proceeds by condensation reaction with evolution of one mole ammonia per two combined moles of monomer through a free radical mechanism. © 1996 John Wiley & Sons, Inc.     

Free-ionic polymerization of isobutyl vinyl ether by radiation

Radiation-induced free-ionic polymerization of isobutyl vinyl ether in bulk system has been studied by dilatometry and electrical conductivity measurement. Some refinements in kinetic treatment of estimate the propagation rate constant k_p from the rate of polymerization and steady-state conductivity were attempted. Polymerization of superdried monomer which gave a half-power dose-rate dependence of R_p was carried out at 0, 25, and 50°C. The k_p value obtained at 25°C and an activation energy for propagation were estimated as 1.2 ± 0.4 × 10⁵ I./mole-sec and 9.6 ± 2.8 kcal/mole, respectively. In isobutyl vinyl ether, a propagation reaction in free-ionic mechanism was found to be characterized with a high frequency factor and presumably higher activation energy, compared with ion-pair mechanism. Discussions were also made as to several contrasting behaviors between the polymerization of alkyl vinyl ethers and other vinyl monomers as styrene both in free-ion and ion-pair mechanisms.     

Immobilization of microbial cells by radiation-induced polymerization of glass-forming monomers and immobilization ofStreptomyces phaeochromogenes cells by polymerization of various hydrophobic monomers

The immobilization ofStreptomyces phaeochromogenes cells was studied by the radiation-induced polymerization of various hydrophobic glass-forming monomers at low temperatures. The glucose isomerase activity of cells immobilized in hydrophobic polymers showed no decrease in activity with repeated use (batch enzyme reaction). Activity increased with increasing monomer concentration in contrast to results with the immobilized enzyme. The hydrophobic polymer composite was microspheric in form. The particle diameter of the composite increased with the increasing monomer concentration.K _m values of the immobilized cells were close to that of intact cells. It was deduced that the cells were trapped on the surface part of the hydrophobic polymer ready to react with the substrate, and not within the matrix where diffusion would play an important role in reaction rates.     

Preparation of polymeric nanocapsules by radiation induced miniemulsion polymerization

In this research, polystyrene (PSt) nanocapsules with liquid cores were prepared by ⁶⁰Co γ-ray radiation induced miniemulsion polymerization, in which N-vinyl pyrrolidone (NVP) was used as the polar monomer. The characterization of polymer was carried out by ¹H NMR. It was verified that during polymerization, graft copolymerization between poly (pyrrolidone) (PVP) and PSt had taken place instead of random copolymerization. The interfacial tension between polymer and water was reduced because of the grafting reaction that had occurred, which was helpful to form nanocapsules. The influence of the ratio of St to NVP, the type and amount of the surfactant and the monomer/dodocane ratio on the particle morphology was studied by TEM. Finally, the releasing process of the synthesized nanoparticles was monitored by UV-vis measurement.     

Metal oxides immobilized fabrics by radiation induced graft polymerization

Radiation induced graft polymerization is effective for adding a new functionality to various forms of existing polymers. Ion-exchange nonwoven fabrics by gamma radiation induced graft polymerization have been used as filters in air and liquid. However, these materials have no capability for removing non-ionic species, such as volatile organic compound and ozone. Manganese oxides immobilized fabrics were developed for removing ozone. In addition, these materials were capable of removing formaldehyde and arsenic. Fine particles of manganese oxides were observed on the fibers. New materials produced by radiation induced graft polymerization and metal immobilization were applicable for purification of contaminants in environment. Manufacturing process is applicable for immobilization of the other metal oxides.     

Immobilization of cobalt disulfophthalocyanine complex on polypropylene

Procedures were developed for chemical activation of polypropylene materials and subsequent immobilization on them of the cobalt disulfophthalocyanine complex. Factors affecting these processes were examined, and the state of the phthalocyanine on the surface of the polypropylene fiber was determined.     

Immobilization of enzymes on a microchannel surface through cross-linking polymerization

A novel and facile method for the preparation of an enzyme-immobilized microreactor has been developed in which enzymes are immobilized as an enzyme-polymer membrane formed on the inner wall of the microchannel by a cross-linking polymerization method; the resulting microreactor shows excellent reaction performance and stability against denaturating agents.     

Vinyl polymerization by a manganese(III) complex

Bis(diethanolamine) manganate(III) was prepared. The polymerization of acrylamide and methacrylamide initiated by this complex in aqueous solution at pH 0.9 was studied at 45°. The rate of polymerization was followed by bromometry, the rate of complex disappearance spectrophotometrically and the molecular weights of the polymers were determined viscometrically. The rate of polymerization was found to be proportional to [Monomer]^1.0. The order with respect to initiator was found to be 0.5 for acrylamide and 0.3 for methacrylamide. The apparent overall activation energies for the polymerizations are ?87 kJ mol^?1 and ?59 kJ mol^?1 for acrylamide and methacrylamide respectively. A kinetic reaction scheme is proposed on the basis of the experimental data; kinetic parameters have been evaluated.     

Solid-state polymerization of acrylamide and some acrylates initiated by ultraviolet radiation

The solid-state polymerization of acrylamide, potassium acrylate, and calcium acrylate by ultraviolet radiation have been investigated. For these polycrystalline monomers both in-source and post-irradiation reactions were studied by using various sources of different intensities at constant temperatures. It is concluded that the polymerization reactions take place primarily on the surfaces of crystals. The high molecular weight material obtained at low conversions show a rapid decrease in intrinsic viscosities, probably due to degradation. Both the rate and degree of polymerization were decreased by the presence of oxygen. The various behaviors observed for these three monomers under ultraviolet radiation were regarded as another indication of the importance of crystal structures upon the solid-state polymerization reactions.     

Study on slow release anti-cancer drugs prepared by radiation induced polymerization

This paper reports the research results which the anticancer drugs Ara-C with controlled slow release were made by radiation induced polymerization of monomers such as methacrylates at room temperature. Our studies showed that not only hydrophilic synthetic polymers but also hydrophobic polymers such as hydrophobic methacrylates (including MMA, EMA, and BMA) could be used to the immobilization. In vitro the rate of drugs release was controlled by the many factors such as the content of drugs, the monomer material, the crosslinking agent, the irradiation dose and the water content, etc.     

Molecular-mass distribution during radical polymerization of acrylates initiated by pulse laser radiation

The analytical expressions for the calculation of the molecular-mass distributions for the polymerization of acrylates initiated by the pulse periodic radiation are derived. The intramolecular chain transfer to the polymer is shown to be responsible for the known abnormalities in the molecular-mass distributions during the polymerization of acrylates. A relationship is derived for the characterization of the periodic structure of the molecular-mass distributions and for confirmation of the applicability of the first peak for estimating the avarage rate constant of chain growth.     

Immobilization of antioxidants via ADMET polymerization for enhanced long-term stabilization of polyolefins

Novel macromolecular antioxidants with multiple hindered phenolic antioxidant moieties along a linear, unsaturated olefinic backbone are prepared and their antioxidative ability in polypropylene (PP) blends is investigated. Firstly, α,ω-diene monomers bearing one alcohol functionality are prepared from 10-undecenoic acid, sourced from the renewable resource castor oil, and are subsequently coupled to hindered phenolic antioxidants to prepare antioxidant bearing α,ω-diene monomers. The preparation of macromolecular antioxidants is then described, via ADMET polymerization of the hindered phenol bearing monomers. Upon blending with polypropylene, the resultant blends show excellent antioxidative stabilization in comparison to commercially available antioxidants and thus represent promising additives for the long-term stabilization of polyolefins in extreme environments, for example in the construction of solar water heating systems.     

Dielectric absorption in polyoxymethylene obtained from tetraoxymethylene crystal by radiation induced polymerization

In order to study the dielectric behavior of polyoxymethylene prepared by radiation-induced solid-state polymerization, large crystals of tetraoxymethylene (2 cm in diameter) were prepared by Bridgman's method and polymerized by γ-rays. The x-ray diffraction pattern of the polymer did not reveal the existence of a so-called amorphous region. In dielectric measurements, only one dielectric absorption was observed in the low-temperature region, while in the high-temperature region ε″ did not change up to about 120°C, where thermal decomposition started. When the specimen was stabilized by acetylating the endgroups in the solid state, ε″ did not change up to about 150°C. This dielectric absorption showed a significant anisotropy for the direction of an applied field. The dielectric absorption was much larger when the electric field was perpendicular to the fiber axis than when the field was parallel. The dielectric absorption was larger in a specimen which was estimated to be more imperfect according to DSC analysis. This leads to the conclusion that the dielectric absorption is attributable to defect regions. On the other hand, the dielectric absorption became larger with increasing numbers of terminal OH groups, and hence it is attributable to the response of the terminal OH groups. Moreover, the dielectric absorption was depressed by the acetylation of the OH groups in the solid state. It is, therefore, concluded that the dielectric absorption observed in polyoxymethylene prepared by solid-state polymerization of tetraoxymethylene is due to the response of terminal OH groups localized in defect regions. Polyoxymethylene crystallized from the melt gives an asymmetric low-temperature absorption. This asymmetry can be ascribed to the superposition of two relaxation processes. When its absorption curve is compared with that of the solid-state polymerized polymer, the low-temperature component can be assigned to crystal defects and the high temperature one to amorphous regions.