Modeling the solubility of ethylene and propylene in a typical polymerization diluent: some selected situations

Atiqullah, Muhammad; Hammawa, Hassan; Hamid, Halim

doi:10.1016/s0014-3057(98)00005-6

Cited by 69 publications

(64 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…When the data presented in Table 1 for propylene solubility in toluene are compared with the data presented previously (Marshtupa et al, 1965;Konobeev and Lyapin, 1967;Atiqullah et al, 1998), it is observed that the solubility data presented here are consistently larger, as illustrated in Figure 3. However, the ratio between the solubility data presented in Table 1 and the solubility data presented previously is constant and equal to 1.25 throughout the experimental region.…”

Section: Resultssupporting

confidence: 66%

“…This is equivalent to changing the empirical parameter a in Equation (2) from 7.4048 (see Table 4) to 7.6997. This effect may be seen very clearly for the data set organized by Atiqullah et al (Atiqullah et al, 1998) for propylene solubility in toluene at 1 atm (1.013 ¥ 10 5 N/m 2 ) at various temperatures, shown in Figure 4. This comparison suggests the existence of some sort of persistent measurement bias between the two independent data sets.…”

Section: Resultsmentioning

confidence: 77%

“…Besides, it is important to emphasize that the data presented here converge smoothly to the ideal solubility of propylene in toluene when pressure decreases in all cases, as shown in Figure 5. In this case, propylene saturation pressures were computed with the Antoine correlation, as described by Atiqullah et al (1998) and Reid et al (1987). Therefore, we believe that the data presented here is more accurate than the ones presented previously.…”

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Propylene Solubility in Toluene and Isododecane

et al. 2003

View full text Add to dashboard Cite

Propylene solubility in toluene and isododecane (2,2,4,6,6‐Pentamethylheptane, CA Registry# 13475‐82‐6) was measured at different temperatures and pressures, similar to the ones normally used to carry out propylene polymerizations through metallocene and Ziegler‐Natta catalysts. Experimental data were obtained with a gravimetric method, where experimental liquid phase compositions are measured at known temperature and pressure conditions. The experimental data were modeled with two different models: the Wilson excess Gibbs free energy model and an empirical model. Both modeling approaches may be recommended for analysis of kinetic data obtained for slurry propylene polymerizations in toluene and isododecane.

show abstract

Section: Resultssupporting

confidence: 66%

Section: Resultsmentioning

confidence: 77%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Propylene Solubility in Toluene and Isododecane

et al. 2003

View full text Add to dashboard Cite

show abstract

“…The solubility of ethylene in the solvent decreases with increasing temperature and, consequently, the monomer concentration drops at higher temperatures, causing a decrease in the propagation reaction. 13 Raising the temperature increases both the propagation rate as well as the probability of chain transfer reactions. Normally, chain transfer reactions have higher activation energies than insertion reactions, and a change in T p strongly affects the rate of chain termination and hence the molecular weight and PDI.…”

Section: Resultsmentioning

confidence: 99%

Molar Mass and Molecular Weight Distribution Determination Of UHMWPE Synthesized Using a Living Homogeneous Catalyst

Talebi¹,

Duchateau²,

et al. 2010

View full text Add to dashboard Cite

Understanding of the physical characteristics of a polymer requires molar mass determination. For the commercially available polymers, having average molar mass below 1 000 000 g/mol, chromatography is the method that is often applied to determine the molar mass and molar mass distribution. However, the application of conventional chromatography techniques for polymers having molar mass >1 000 000 g/mol becomes very challenging, and often the results are disputed. In this article, melt rheometry based on the "modulus model" is utilized to measure the molar mass and polydispersity of ultra highmolecular-weight polyethylenes (UHMWPEs) having molar mass >1 000 000 g/mol. Results are compared with the chromatography data of the same polymer samples and the boundary conditions where the chromatography technique fails, whereas the rheometry provides the desired information is discussed. The rheological method is based on converting the relaxation spectrum from the time domain to the molecular weight domain and then using a regularized integral inversion to recover the molecular weight distribution curve. The method is of relevance in determining very high molar masses (exceeding 3 000 000 g/mol) that cannot be ascertained conclusively with the existing chromatography techniques. For this study, UHMWPEs with various weight-average molar masses, where the number-average molar mass exceeds >1 000 000 g/mol, are synthesized. Catalyst used for the synthesis is a living homogeneous catalyst system: MAO-activated bis(phenoxy imine) titanium dichloride. The rheological behavior of the thus synthesized nascent reactor powders confirms the disentangled state of the polymer that tends to entangle with time in melt.

show abstract

“…Generally, elevated temperatures will result in higher chain-propagation and chain-transfer rates, which would be expected to increase the catalyst activity. However, the decrease in ethylene solubility in toluene [8] and higher rates of catalyst deactivation may have occurred at higher temperature. A combination of these effects is likely to account for the dependence of catalytic activity and polymer characteristics on temperature.…”

Section: Resultsmentioning

confidence: 99%

A Novel Highly Active Iron/2,6-Bis(imino)pyridyl Catalyst for Ethylene Polymerization

Wang

Qiu

et al. 2001

Macromol. Rapid Commun.

View full text Add to dashboard Cite

A novel highly active catalyst 2,6‐bis[1‐(2‐methylnaphthylimino)ethyl]pyridineiron(II) chloride (1) is reported for ethylene polymerization. Compared with 2,6‐bis[(1‐naphthylimino)ethyl]pyridineiron(II) chloride (2) reported recently, catalytic activities of this new complex are high with maximum activity 6.51×106 g PE·mol–1·Fe·h–1·bar–1 at 40°C. The activity of the catalyst, and the molecular weight and melting temperature of the polymers depend on the methylaluminoxane/1 molar ratio and polymerization temperature.

show abstract

Modeling the solubility of ethylene and propylene in a typical polymerization diluent: some selected situations

Cited by 69 publications

References 32 publications

Propylene Solubility in Toluene and Isododecane

Propylene Solubility in Toluene and Isododecane

Molar Mass and Molecular Weight Distribution Determination Of UHMWPE Synthesized Using a Living Homogeneous Catalyst

A Novel Highly Active Iron/2,6-Bis(imino)pyridyl Catalyst for Ethylene Polymerization

Contact Info

Product

Resources

About