HDPE/propane

Figure 12 shows the results for the modeling of the solubility of the copolymer poly(ethylene-co-l-butene) in propane. The pure-component parameters for poly (ethylene) (HOPE), poly(l-butene), and propane as well as the binary parameters for HDPE/propane and poly(l-butene)/propane were used as determined for the homopolymer systems. 

Borealis A/S Polyethylene Ethylene, butene Slurry-loop process uses supercritical propane and a series gas-phase reactor produce tailor-made MW, enhanced LLDPEs, MDPEs, HDPEs 4 2000... 

The data in tables 9.1 and 9.2 were taken from Watkins et al. (1991) who demonstrate the impact of the crystallization boundary on the fractionation behavior of high-density polyethylene (HOPE). The second critical end point temperature for this sample of HOPE in propane is approximately 125°C. The data in table 9.3 show that HDPE can be selectively fractionated with respect to molecular weight across its entire molecular weight distribution using an isothermally increasing pressure profile in the liquid-gas region of the phase diagram. 

Table 9.1 Properties of Fractions of HDPE Obtained by an Isothermally Increasing Pressure Profile with Propane at 130°C, a Temperature Above the Melting Point of the Parent Material...

Williams and Williams27 have studied the pyrolysis of both HDPE and LDPE in a fixed bed reactor. In each experiment the temperature was varied between 25 and 700 °C. The products were swept down through the bottom of the reactor by a nitrogen flow and separated into several fractions by condensation at different temperatures. Two main fractions were recovered as products from the HDPE and LDPE pyrolysis gases with a yield of 15-17 wt% and oils with yields in the range 80-84 wt%. The gases were rich in ethylene, propylene and butene, with lower proportions of saturated hydrocarbons (methane, ethane, propane and butane). The oils produced were analysed by FTIR and GPC,... 

In some cases, lack of noticeable influence of electron beam radiation on the values of tensile and Charpy impact strengths of 24-23-21-15-17 LDPE-HDPE-PP-PS-PET blends (based on recycled polymers) compatibilized with 1% trimethylol propane trimethylacrylate (TMPTMA) were found. Zenkiewicz et al. ° explained this lack of influence by the protective action of aromatic rings of PS and PET that hindered cross-linking. In the same article, the addition of 10% of styrene-ethylene/butylene-styrene elastomer grafted with maleic anhydride (SEBS-g-MA) led to the great increase of both tensile and Charpy impact strengths. 

The company s ethylene expansion project was one of the six projects in China s ninth five-year plan for 1996 to 2000. After a temporary suspension of all ethylene and LDPE projects in China, the company completed its Ethylene Project in late 2001, increasing its annual ethylene production rated capacity to 710 000 tons. As an integral part of this Project, the company s LDPE facilities were also expanded from 180 000 tons to 380 000 tons. It is also a major producer of HDPE with 140 000 metric tonnes of capacity. A 200 000-ton PP facility was completed in 1998 and a butyl rubber facility in 1999. Only a limited number of butyl rubber producers exist worldwide and Sinopec Beijing is among the first to produce the material in China. Other major products include styrene-butadiene rubber (SBR 1500 tonnes per year), cis-1,3 butadiene rubber (BR), EPDM (40 000 tonnes per year), polystyrene resin, reinforced polypropylene, stretching film, ethylene, propylene, propane, ethylene glycol, p-xylene, styrene, benzene, toluene, xylene, alkylbenzene, and other basic organic chemicals. 

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