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SynopsisAn approach to the problem of producing poly(viny1 chloride) (PVC) graft copolymer exhibiting good mechanical properties and electrical resistance that suits its uses as an electrical insulator has been investigated. Graft copolymerization of methyl methacrylate (MMA) onto PVC using yradiation as initiator has been studied. PVC was chemically modified, and the effect of the change in its chemical and physical structure on its properties was investigated. In this grafting system, different solvents were tried and it was found that the most suitable diluent for the grafting of MMA onto PVC films is methanol. An appreciable improvement in tensile properties of the graft copolymer was achieved. The most suitable degree of grafting, concerning electrical insulation efficiency, was found to be near 80%. Gel determination in the graft copolymer was carried out, and a crosslinked network structure was formed. Increasing the crosslinking content in the graft copolymer leads to a decrease in the extent of swelling due to the less diffusivity of the solutions through such network structure.

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Microbial infections are currently a widespread disease in hospitals and community health centres and are a major cause of death worldwide. In pursuit of searching new antimicrobial agents, coumarin linked to thiazoles, pyridines and pyrazoles have been developed and evaluated for their antimicrobial properties against two Gram + bacteria, two Gram − bacteria as well as two fungi. Some of the prepared coumarins displayed high to moderate activity against the tested microorganisms with respect to the reference drugs. However, compound 3 exhibited antimicrobial effect equal to the reference drug Ciprofloxacin for Gram − baceria Enterobacter cloacae. Compound 12 was found to be the most potent compound against Bacillus pumilis with MIC of 7.69 (µmol/ml). Compounds 3, 4 and 12 showed remarkable activity against Streptococcus faecalis with MIC of 14.34, 3.67 and 15.36 (µmol/ml), respectively. Regarding Escherichia coli, most compounds recorded high to moderate MIC values (4.73–45.46 µmol/ml). Moreover, in case of E. cloacae compound 9 was the most potent compound with MIC value of 22.76 (µmol/ml).

Das Bis‐N‐tosylphthalsäurediamid (I) reagiert mit Grignardverbindungen (II) zu Tosylhalbaminalen (III), Tosylaminocarbonsäureamiden (IV), Hydroxyindolinonen (V) oder Hydroxy‐ 55 methylbenzamiden (VI).