Search results
Results From The WOW.Com Content Network
The p-xylene is then separated out in a series of distillation, adsorption or crystallization and reaction processes from the m-xylene, o-xylene, and ethylbenzene. Its melting point is the highest among this series of isomers, but simple crystallization does not allow easy purification due to the formation of eutectic mixtures.
p-Xylene is the principal precursor to terephthalic acid and dimethyl terephthalate, both monomers used in the production of polyethylene terephthalate (PET) plastic bottles and polyester clothing. 98% of p-xylene production, and half of all xylenes produced is consumed in this manner. [10] [14] o-Xylene is an important precursor to phthalic ...
Solid properties Std enthalpy change of formation, Δ f H o solid? kJ/mol Standard molar entropy, S o solid? J/(mol K) Heat capacity, c p? J/(mol K) Liquid properties Std enthalpy change of formation, Δ f H o liquid: −24.4 kJ/mol Standard molar entropy, S o liquid: 247 J/(mol K) Enthalpy of combustion, Δ c H o: −4552 kJ/mol Heat capacity ...
In the petroleum refining and petrochemical industries, the initialism BTX refers to mixtures of benzene, toluene, and the three xylene isomers, all of which are aromatic hydrocarbons. The xylene isomers are distinguished by the designations ortho – (or o –), meta – (or m –), and para – (or p –) as indicated in the adjacent diagram.
Isotactic & atactic polypropylene is soluble in p-xylene at 140 °C. Isotactic precipitates when the solution is cooled to 25 °C and atactic portion remains soluble in p-xylene. The melt flow rate (MFR) or melt flow index (MFI) is a measure of molecular weight of polypropylene. The measure helps to determine how easily the molten raw material ...
Despite the observed chemistry of para-xylylene (i.e. its rapid polymerization to poly-p-xylylene), which suggests the compound exists as a diradical, physical evidence unanimously concludes that the lowest electronic state of p-xylylene is a closed shell singlet. Additionally, several computational methods confirm this assignment. [13]
Liquid solvents are simpler and generally have lower manufacturing costs but are sensitive to surface imperfections that may cause inconsistent or unpredictable bonding. [6] Some solvents available may not react with the thermoplastic at room temperature but will react at an elevated temperature resulting in a bond. [ 2 ]
A pipe is a tubular section or hollow cylinder, usually but not necessarily of circular cross-section, used mainly to convey substances which can flow — liquids and gases , slurries, powders and masses of small solids. It can also be used for structural applications; a hollow pipe is far stiffer per unit weight than the solid members.