Calorimetric evaluation of polymerization thermokinetics of styrene, alpha-methylstyrene and trans-beta-methylstyrene

According to literature and our research, the styrene polymerization mechanism is identified by alpha-methylstyrene (AMS). This study investigated the basic exothermic behavior of styrene and its major derivatives, AMS, and trans-beta-methylstyrene (TBMS), by two calorimeters, differential scanning calorimetry (DSC) and thermal activity monitor (TAM), to compare and evaluate their thermal kinetics on polymerization. DSC and TAM were employed for dynamic scanning and isothermal ageing tests to calculate thermokinetic parameters of styrene and styrene containing 10ppm 4-tertiary-butylcatechol (TBC), AMS, and TBMS. Certain prominent differences were observed and discussed between AMS and TBMS obtained from DSC and TAM. All of the results could be provided to the relevant plants for lessening the degree of hazard. Results indicated that styrene, AMS, and TBMS have potential exothermic hazards, especially during the higher temperature.

Methanosarcina mazei strain O1M9704, methanogen with novel tubule isolated from estuarine environment

A new methanogenic isolate, designated as strain O1M9704 (=OCM 667), was isolated from the sediment of the estuarine environment in Eriln Shi, Taiwan. This strain grew on trimethylamine and methanol, but it did not catabolize H2-CO2, acetate, or formate. Cells grew optimally at 37 degrees C with 0.5% NaCl in neutral pH. The cells were stained Gram-negative, nonmotile, irregular coccus 0.3-0.6 microm in diameter. A comparison of 16S rDNA sequences phylogenetically related strain O1M9704 to Methanosarcina mazei. Gas vacuoles were observed both under phase contrast microscope and in thin sections in the electron microscope. Negative stain of electron micrographs showed a novel character of strain O1M9704. with tubule structure extended out of the cells. The tubule structure and gas vacuoles may benefit the adaptation of methanoarchaea in estuarine environment.

Characterization of Methanosarcina mazei N2M9705 isolated from an aquaculture fishpond

A new methanogenic isolate, designated as strain N2M9705 (=OCM 668), was isolated from an aquaculture fishpond near Wang-gong, Taiwan. This strain grew on trimethylamine and methanol, but it did not catabolize H2-CO2, acetate, or formate. The cells were stained Gram-negative, nonmotile, irregular coccus 0.6-0.8 micrometer in diameter. Gas vacuoles were observed and cell aggregated to form various sizes of granules. Cells grew optimally at 32 degrees -37 degrees C with 1% NaCl. The pH range of growth was 6.2-7.4, and higher pH inhibited the cell growth. The cells grew well in minimal medium, but growth was greatly stimulated by yeast extract and peptone. A comparison of 16S rDNA sequences of this organism phylogenetically related to Methanosarcina mazei. This is the first report of methyltrophic methanogenic isolated from an aquaculture fishpond.