CATALYST FOR POLYMERIZATION OF ETHYLENE, CONTROLLING DISTRIBUTION OF MOLECULAR MASS OF ETHYLENE POLYMERS AND A METHOD FOR POLYMERIZATION OR COPOLYMERIZATION OF ETHYLENEA vanadium-based catalyst is treated with certain oxygen-containing compounds as a means of narrowing and effectively regulating the molecular...
This chapter gives an overview of chemical methods for analysing small molecular mass materials produced from coal pyrolysis in petroleum refinery products and in biomass pyrolysis products. These molecules are generally below 500 mass units. Methods include mass spectrometry, with gas chromatography in ...
The molecular mass of a substance is the mass of one molecule of that substance, in unified atomic mass units (Drews, 1998; Speight, 2015). This is distinct from the relative molecular mass of a molecule, frequently referred to by the term molecular weight, which is the ratio of the mass...
g, h, Mass spectrum of putative MeSA produced by plants (g) and the authentic MeSA standard (h). i, j, Comparison of the aerial MeSA concentrations in chambers containing either MeSA dissolved lanolin paste or aphid attacked WT plants by GC-MS analysis. Experiments were repeated at least ...
where x is the mass fraction of MOHC in MOF. It can be discovered from formula (2) that, when the sum of (∫CpdT)MOFs and ∆hdesorption is greater than ∆hFluid, MOHCs can enhance the energy storage property of the refrigerant. At present, research on the thermophysical property of...
It was observed that high molecular weight chitosan had higher positive effect on the shelf life of Sentiabrskaya and Anykšta cultivars than VIR2 . Low molecular weight chitosan was found effective on VIR2 . 展开 关键词: Edible coating Firmness testing Mass loss Phenolic compounds Vitamin C ...
Viktorova, E.N., Korolev, A.A., Ibragimov, T.R.et al.Monolithic capillary columns based on ethylene glycol dimethacrylate for separation of polymers by molecular mass.Polym. Sci. Ser. A55, 204–211 (2013). https://doi.org/10.1134/S0965545X13030085 ...
Growing concern has arisen from the quasi-exponential increase in the numbers and quantities of man-made chemicals that presently are in current use, and their potential effects on human health, especially their delayed effects on degenerative diseases s
are exactly the same, then the number-average and weight-average molecular weights are exactly the same and the polydispersity is “1.” The larger the molar-mass dispersity index, the wider the molecular weight distribution. Themolecular weight rangecan affect many properties of plastic materials....
The crystal structure in crystalline polymers lacks both the sorption sites as well as the mobility of the chains which leads to mass transfer of gas molecules; that is low permeability. Semicrystalline polymers have discrete sections of rigid chain packing on a macroscopic scale as shown in Fig....