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The reaction of 2,4-dihydroxybenzophenone (DHBP) with N-[4-(chlorocarbonyl)phenyl] maleimide provided a novel monomeric ultraviolet (UV)-absorber in the presence of triethylamine. This reactive maleimide was bound onto the backbone of high density polyethylene (HDPE) by melt-grafting in a mini-mixer. The extent of grafting of the monomeric maleimide was quantified by infrared (IR) spectroscopy. To find the optimal grafting conditions, the dependence between reaction temperature, time and the concentration of the monomeric UV-absorber were investigated on the grafting yields. The photo-stabilizing effect of the grafted HDPE was evaluated in a xenonarc weathering apparatus and compared with HDPE mixed with the UV-absorbers using the carbonyl index of the IR spectrum. The grafted HDPE retarded the light initiated oxidation to a greater extent.

A novel monomeric UV-absorber was prepared by the reaction of 2,4-dihydroxybenzophenone with N-4-chlorocarbonylphenylmaleimide in the presence of triethylamine. This reactive maleimide was grafted onto polypropylene (PP) by the thermal melt-processing in a mini-max-moulder. IR spectroscopic method was used for the quantitative determination of the extent of grafting of monomeric maleimide. To find the optimal reaction conditions, the dependence of reaction temperature and time and the concentration of monomeric UV-absorber was investigated on the grafting yields. The photooxidative effect of the grafted PP was evaluated in the weatherometer comparing to the PP mixed with UVabsorbers using the carbonyl index of IR spectrum. The grafted PP showed an excellent anti-photooxidative effect.

Novel beta-hydroxy propenamides as analogues of the active metabolite of leflunomide (A 771726) were synthesized and evaluated for their inhibitory activity on dihydroorotate dehydrogenase (DHODH) in an investigation into their immunosuppressive activity. Compounds 2a, 3a, and 3h were approximately 4-40 times more potent than leflunomide in their activity while they were-less active than A 771726.