Degradation catalytic

Oblimersen sodium is a DNA antisense oligonucleotide designed to specifically bind to human bcl-2 mRNA, resulting in catalytic degradation of bcl-2. This results in decreased translation of the protein Bcl-2, which is a cellular antiapoptotic protein. Thus, oblimersen enhances sensitivity to chemotherapy by shifting the intracellular balance to a state in which the cells are more likely to be killed by apoptosis. Currently, it is used in combination chemotherapy for treating advanced melanoma. 

CATALYTIC DEGRADATION OF IGH DENSITY POLYETHYLENE AND POLYPROPYLENE INTO LIQUID FUEL IN A POWDER-PARTICLE FLUIDIZED BED... 

The catalytic degradation of HDPE and PP was carried out in a powder-particle fluidised bed with an inside diameter of 25 mm. Two catalysts were used as the medium fluidisation particles. These were F9 (with a composition of silica alumina sodium oxide of 32 48 20 wt.percent) and silica/alumina (SA, with a composition of silica alumina of 71 29 wt.percent). Liquid fuel was produced in high yield. SA produced a higher yield of liquid fuel nd a more valuable gas product between temperatures of400-550C. Over 86 wt.percent conversion... 

Journal of Applied Polymer Science 73,No.7, 15thAug.l999, p.1139-43 MECHANISM STUDIES ON THE CATALYTIC DEGRADATION OF WASTE POLYSTYRENE INTO STYRENE IN THE PRESENCE OF METAL POWDERS... 

THERMAL AND CATALYTIC DEGRADATION OF MUNICIPAL WASTE PLASTICS INTO FUEL OIL... 

The catalytic degradation of polypropylene was carried out over ferrierite catalyst using a thermogravimetric analyzer as well as a fixed bed batch reactor. The activation of reaction was lowered by adding ferrierite catalyst, which was similar with that from ZSM-5. Ferrierite produced less gaseous products than HZSM-5, where the yields of i-butene and olefin over ferrierite were higher than that over HZSM-5. In the case of liquid product, main product over ferrierite is C5 hydrocarbon, while products were distributed over mainly C7-C9 over HZSM-5. Ferrierite showed excellent catalytic stability for polypropylene degradation. 

Fig. 3. Product yield as a function of lapsed time for thermal and catalytic degradation of LDPE...

Fig. 5. Cumulative liquid product 3deld from thermal and catalytic degradation of LDPE at different temperature...

The ZSM-5 deactivation rate is decreased with progress of degradation reaction. And also the catalytic degradation of the plastics occurred at lower reaction temperature than the thermal degradation by about 40-60 °C. 

The catalytic degradation of PS was carried out in a semi-batch reactor where nitrogen is continuously passed with a flow rate of 30 mL/min. A mixture of 3.0 g of PS and 0.3 g of the catalyst was loaded inside a Pyrex vessel of 30 mL and heated at a rate of 30 C/min up to the desired temperature. The distillate from the reactor was collected in a cold trap(-10 °C) over a period of 2 h. The degradation of the plastic gave off gases, liquids and residues. The residue means the carbonaceous compounds remaining in the reactor and deposited on the wall of the reactor. The condensed liquid samples were analyzed by a GC (HP6890) with a capillary column (HP-IMS). 

Catalytic degradation of high density polyethylene over post grafted MCM-41 catalyst kinetic study... 

In this study, post-synthetic metal grafting was used to incorporate A1 into MCM-41 (Al-MCM-41-P), which was probably the first attempt at the catalytic degradation of waste plastics. The objective of this study was to investigate the kinetic aspect of high-density polyethylene (HDPE) over Al-MCM-41-P. 

Prechromatographic derivatization reactions re usually favored when it is desired to modify the properties of the sample to enhance stability during measurement (i.e., minimize oxidative and catalytic degradation, etc.), to improve the extraction efficiency of the substance during sample cleanup, to improve the chromatographic resolution, or to simplify the optimization of the reaction conditions [698-702]. As both pre- and postchromatographic methods enhance the sensitivity and selectivity of the detection process a choice between the two methods will usually depend on the chemistry involved, ease of optimization, and which method best overcomes matrix and reagent interferences. 

The rate of drug release (E) from the eroding matrix is controlled by (a) the chemical properties of the system - the hydrolytic and the neutralizing process at the boundary of the device, catalytic degradation of the polymer and the intrinsic backbone reactivity, and (b) several concomitant physical processes such as water diffusivity, water solubility, water partitioning, etc. 

Lai T-L, Lee C-C, Wu K-S, Shu Y-Y, Wang C-B (2006) Microwave-enhanced catalytic degradation of phenol over nickel oxide. Appl Catal B 68 147-153... 

Wang Y-Q, Gu B, Xu W-L (2009) Electro-catalytic degradation of phenol on several metal-oxide anodes. J Hazard Mater 162 1159-1164... 

Mixtures of C4 alkene isomers (largely isobutene) are polymerised commercially in contact with low levels of aluminium chloride (or other Lewis acid) catalysts. The highly exothermic runaway reactions occasionally experienced in practice are caused by events leading to the production of high local levels of catalyst. Rapid increases in temperature and pressure of 160°C and 18 bar, respectively, have been observed experimentally when alkenes are brought into contact with excess solid aluminium chloride. The runaway reaction appears to be more severe in the vapour phase, and a considerable amount of catalytic degradation contributes to the overall large exotherm. 

Keywords polyolefins, PVC, catalytic degradation, zeolite, hydrotalcites. 

The difference of the polyolefins and the PVC in the catalytic degradation can be seen in Fig. 3 the decomposition of PVC takes place at least in two steps, the first is due to the release of HC1 with 300 °C characteristic temperature, the second peak corresponds to the pyrolysis of the residual hydrocarbon framework (440 - 470 °C temperature range). 

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