Acetone

About: Acetone is a research topic. Over the lifetime, 9458 publications have been published within this topic receiving 120867 citations. The topic is also known as: propanone & dimethylketone.

Hydrolytic degradation of films prepared from blends of high and low molecular weight poly(DL‐lactic acid)s

Abstract: Biodegradable films were prepared by casting acetone solutions of mixtures of a high molecular weight poly(DL-lactic acid) (HMW-PLA50) with 0, 10, and 30% w/w poly(DL-lactic acid) oligomers (LMW-PLA50), before drying. From size exclusion chromatography (SEC) it was shown that degradation occurred during film processing, in agreement with the acid-catalyzed degradation of polyesters. The higher the content of LMW-PLA50, the larger the decrease of the molar masses. The three selected film formulations were then allowed to age in isoosmolar 0.13M, pH 7.4 sodium phosphate buffer at 37 degrees C. The hydrolytic degradation was monitored by using various techniques, namely weighing to quantify water absorption and weight loss, SEC to evaluate molar mass changes, head space gas chromatography to assess the desorption of residual acetone, and enzymatic assay of the L-lactic acid released in the aging media. The presence of LMW-PLA50 clearly accelerated film degradation. Moreover, it was shown that the mechanism of degradation greatly depended on the content in the oligomers.

Acetone, methyl ethyl ketone, ethyl acetate, acetonitrile and other polar aprotic solvents are strong inducers of aneuploidy in Saccharomyces cerevisiae.

Abstract: A diploid yeast strain D61.M was used to study induction of mitotic chromosomal malsegregation, mitotic recombination and point mutation. Several ketones (including acetone and methyl ethyl ketone) and some organic acid esters (including the methyl, ethyl and 2-methoxyethyl esters of acetic acid) and acetonitrile strongly induced aneuploidy but not recombination or point mutation. Only diethyl ketone induced low levels of recombination and point mutation in addition to aneuploidy. Related compounds were weak inducers of aneuploidy: methyl n-propyl ketone, the methyl esters of propionic and butyric acid, acetic acid esters of n- and iso-propanol and ethyl propionate. No mutagenicity was found with n-butyl and isoamyl acetate, ethyl formate, acetyl acetone (2,5-dipentanone) and dioxane. Methyl isopropyl ketone induced only some recombination and point mutation but no aneuploidy. Efficient induction was only observed with a treatment protocol in which growing cells were exposed to the chemicals during a growth period of 4 h at 28 degrees C followed by incubation in ice for more than 90 min, usually overnight for 16-17 h. Aneuploid cells could be detected in such cultures during a subsequent incubation at growth temperature if the chemical was still present. Detailed analysis showed that there was a high incidence of multiple events of chromosomal malsegregation. It is proposed that the mutagenic agents act directly on tubulin during growth so that labile microtubules are formed which dissociate in the cold. When cells are brought back to temperatures above the level critical for reassembly of tubulin and allowed to grow, faulty microtubules are formed.

Partial Oxidation of Alcohols on Visible-Light-Responsive WO3 Photocatalysts Loaded with Palladium Oxide Cocatalyst

Abstract: Particles of tungsten oxide loaded with a palladium oxide cocatalyst (PdOx/WO3) exhibit higher selectivity in comparison to other photocatalysts, such as Pt/WO3, Pd/TiO2, and Pt/TiO2, in the partial oxidation of alcohols such as 2-propanol to the corresponding aldehydes or ketones (e.g., 80% selectivity for acetone production with ca. 96% conversion of 2-propanol) in water containing molecular O2. A detailed investigation of 2-propanol oxidation as a model reaction revealed significant differences between the reactivities of the WO3 and TiO2 systems. On TiO2 photocatalysts, complete decomposition to CO2 proceeded readily, due to the occurrence of direct oxidation of 2-propanol and acetone adsorbed by holes, resulting in significantly low selectivity for partial oxidation. On the other hand, the rates of acetone peroxidation on WO3 photocatalysts were much lower than those on TiO2 due to the low affinity of the WO3 surface to the substrates, particularly acetone. The low affinity of the WO3 surface also en...