A series of bis(carbamate) derivatives of 1,2-substituted 4,5-bis(hydroxymethyl)imidazoles were prepared and evaluated against murine P388 lymphocytic leukemia. Electron-withdrawing substituents at either N-1 or C-2 gave rise to inactive compounds. However, electron-donating substituents gave active compounds and the 2-(methylthio)-1-methyl derivative 2i (carmethizole), as the bis(N-methylcarbamate), was found to be very active. The derivative 2i, referred to by the name carmethizole, was also shown to be active against the MX-1 mammary xenograft, the human amelanotic melanoma cell line (LOX) xenograft, the M5076 sarcoma, and L1210 lymphocytic leukemia. The solution stability, water solubility, pKa, and log P of carmethizole are also reported.
Most polyurethane elastomers in the market place are based on aromatic isocyanates. This is partially due to the higher cost of aliphatic isocyanates compared with aromatic isocyanates which are commonly used by the industry. However, more importantly, it has been the performance deficiency of polyurethane elastomers based on commercial aliphatic isocyanates that has significantly limited their use. Though aliphatic-based polyurethane elastomers possess increased resistance to hydrolysis and thermal degradation in addition to greater light stability, these elastomers often experience a decrease in physical-mechanical properties when compared with aromatic isocyanate-based materials. In this study, we investigated elastomers based on 1,3 and 1,4-bis(isocyanatomethyl)cyclohexane, an experimental diisocyanate recently developed by The Dow Chemical Company. The physical properties of the elastomers are reported and discussed in comparison to similar elastomers prepared from commercially available aliphatic and aromatic isocyanates.
The hydroformylation of seed oil based fatty acid methyl esters leads to aldehyde intermediates that can be hydrogenated to give novel seed oil based monomers. In this study, the seed oil based monomers were polymerized with low molecular weight diols to produce novel aliphatic polyester polyols with very low viscosities. The seed oil polyester polyols provide environmentally friendly (green) coating formulations with low volatile organic compound emissions which lead to coatings with superior physical properties, such as exceptional hydrolytic resistance and flexibility. From these polyester polyols, waterborne polyurethane dispersions were also developed with excellent stability resulting in coatings with superior physical properties (i.e., good toughness and abrasion resistance), and exceptional hydrolytic and acid resistance.
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