Roustam Aliev

Graft polymerization of acrylic acid onto polycarbonate by the preirradiation method

Abstract Graft polymerization of acrylic acid from the monomer solutions in water, acetone and water–acetone mixture onto bisphenol-A polycarbonate (PC) was carried out by the method of preirradiation in air. Effects of dose, temperature and monomer concentration on grafting were investigated, the optimal values of these parameters are 150 kGy, 80°C and 50 wt%, respectively. Effectiveness of grafting as well as transparency, fragility, hydrophilicity and crosslinking of the modified PC depend on the monomer–solvent compositions used.

Radiation grafting of dimethylaminoethylmethacrylate onto poly(propylene).

Radiation-induced grafting of dimethylaminoethylmethacrylate onto poly(propylene) films by preirradiation method in presence of air was investigated. The effects of monomer concentration, preirradiation dose and temperature on grafting value as well as the effect of grafting value on crystallinity of the modified polymer were determined.

Immobilization of streptavidin-horseradish peroxidase onto a biotinylated poly(acrylic acid) backbone that had been radiation-grafted to a PTFE film.

Films of polytetrafluoroethylene (PTFE) were modified by radiation graft polymerization of acrylic acid (AAc). Optimal conditions for efficient AAc grafting were studied, including pre-irradiation dose in air, monomer concentration, temperature and time of the grafting process. Carboxylic groups of the grafted polyAAc were activated with carbodiimide (EDC) for biotinylation by reaction with 5-(biotinamido) pentylamine. Streptavidin-horseradish peroxidase (SA-HRP) was immobilized by affinity complexation of the SA with the biotin groups on the PTFE surface. The amount of active HRP immobilized on the PTFE films was determined as a function of the extent of polyAAc grafting. This study has demonstrated the utility of combining the processes of (a) radiation grafting of polymers with reactive groups onto inert polymers such as PTFE, (b) biotinylation of the graft polymer reactive groups, (c) immobilization of streptavidin on the biotinylated surface sites, followed by (d) immobilization of biotinylated, biologically active molecules via complexation of their conjugates with streptavidin. In this study, the last two steps were combined by immobilizing the complex of streptavidin and biotinylated HRP onto the biotinylated surface sites. The unique nature of this process is the ability to immobilize biotinylated molecules on an inert surface as PTFE.

Effect of dose rate and oxygen on radiation crosslinking of silica filled fluorosilicone rubber

Abstract Fluorosilicone (polymethyltrifluoropropylsiloxane) rubber containing silica filler was irradiated with γ-rays and accelerated electrons in air, argon and vacuum. Doses up to 0.5 MGy and dose rates of 1.4 and 10 3 Gy/s were used. The absorbed dose distribution across the rubber thickness during electron irradiation was determined. Oxidation, swelling in ethyl acetate and mechanical properties of this rubber depended on the conditions of irradiation that testified to different effectiveness of the rubber radiation crosslinking under these conditions. Effects of dose rate, diffusion of oxygen into rubber during irradiation, local heating and the oxygen desorption from the filler particles during the electron irradiation are considered for explanation of these differences.

Radiation-induced crosslinking of polyvinyltrimethylsilane in the presence of ethylene glycol dimethacrylate and allyl methacrylate

Abstract Radiation-induced crosslinking of homogeneous glassy polyvinyltrimethylsilane was carried out either by the γ -irradiation of the polymeric films containing 3–20 wt% of ethylene glycol dimethacrylate or by the radiation-induced grafting of allyl methacrylate from vapour phase onto films made of pure polymer. The dependence of grafting value on the absorbed γ -irradiation dose and film thickness was investigated. The modified films were analyzed for the sol/gel content and the dependence of gel fraction yield of crosslinked polymer on absorbed dose, concentration of the crosslinking agents and film thickness. The radiation-chemical yields of crosslinking and degradation as well as gelation doses were calculated. The permeability of oxygen and nitrogen through the crosslinked films was determined.