LDPE-water partition coefficient coefficients

Adopted from the original reference, from Mackay et al. (1992a), or from US EPA (2003), in order of availability. 1. Calculated from LDPE-water partition coefficients (Reynolds et al, 1990) and triolein-water partition coefficients (Chiou, 1985) 2. Huckins et al. (1999) 3. Huckins et al. (2002a) 4. Booij et al. (2003) 5. Huckins et al. (2004). 

To calculate the cis-3-hexenol LDPE/water partition coefficient use Eqs. (4-98), (4-101) and Eq. (4-50). The W, values are taken from Table 4-6. 

Einally, LDPE SPMDs with grass carp lipid were exposed for 21 d to 14C-2,2, 5,5 -TCB, 14c-3,3, 4,4 -TCB, i c-mirex and i c-fenvalerate, whereas SPMDs with triolein or lecithin were exposed to only " C-2,2, 5,5 -TCB. After 21 d, the largest mass fraction of these test chemicals ( " C-mirex was an exception) was in the triolein. The C-2,2, 5,5 -TCB log triolein-water partition coefficient was 6.01, whereas the " C-2,2, 5,5 -TCB partition coefficients for the grass carp lipid-water and lecithin-water systems were 30% and 35% lower, respectively. Comparison of these data to literature log AlowS of 2,2, 5,5 -TCB showed that the partition coefficients for the grass-carp lipid and the lecithin were not significantly different from median values reported for the log ATow of " C-2,2, 5,5 -TCB. However, the partition coefficient of 2,2, 5,5 -TCB in triolein and water in direct... 

Calculated from LDPE-water partition coefficiaits (Lefkovitzetal., 1996) and triolein-water partition coefficients (Chiou, 1985) 2. Huckins et al. (2002a) 3. Booij et al. (2003). 

To calculate the IRGANOX/water partition coefficient use Eqs. (4-98), (4-101) and (4-50) in combination with Table 4-6. The average-value Wj(G/p> = -4 is used for the ester increment in LDPE. For the 2,6-di-tert-butyl-phenol increment no value can be extracted from Table 4-6. But comparing the increments in Table 4-8 one half of the value for primary-alcohol is taken and one can use Wj(G/p) = 10 for LDPE. A four-fold branching has to be considered and this gives Wj(G/P) = 4 x (-5) = -20 (as average) ... 

A test set of 6 to 13 aroma compound partition coefficients between different food contact polymers (low density polyethylene (LDPE), high density polyethylene (HDPE) polypropylene (PP), polyethylene terephthalate (PET), polyamide (PA)) and different food simulant phases (water, ethanol, aqueous ethanol/water mixtures, methanol, 1-propanol) were taken from the literature (Koszinowski and Piringer, 1989, Baner, 1992, Franz, 1990, Koszinowski, 1986, Franz, 1991, Baner, 1993, Piringer, 1992). Table 4-2 shows the test set of 13 different aroma compounds, with their properties and their structures. The experimental data were compared to estimations using different estimation methods of UNIFAC-FV, GCFLORY (1990), GCFLORY (1994) and ELBRO-FV. 

Calculate the partition coefficient of cis-3-hexenol between LDPE and water and between LDPE and 100 % ethanol. 

Table 9-9 Partition coefficients of organic compounds between polymers (LDPE, PVC) and several ethanol/water-mixtures at 23 °C.

The K values increase rapidly for completely unpolar n-alkanes with increasing water content (Table 9-11). Because of the very low solubility of hydrocarbons and most organic compounds in pure water, the partition coefficients for LDPE/water are either obtained by extrapolating the K values from Table 9-10 to 100 % water, or calculated from two independent measurements of the partition coefficients between... 

LDPE/octanol (KP/0) and octanol/water (K0/w)- The partition coefficient for LDPE/ water (KP/W) results then from KP/W = KP/0 K0/w (Table 9-12). 

Table 9-12 Partition coefficients of some aroma octanol and water at 23 °C. compounds between LDPE and octanol and between ...

The consequences of the above results on the partition of aromas and aroma compounds between products and a plastic package can be seen in the values in Table 9-13. It can be seen from the partition coefficients that the values for medium polarity to non-polar substances partitioned between the two wine samples and LDPE are one to two orders of magnitude greater than the partitioning of the same substances between milk and LDPE (limonene, diphenylmethane, diphenyloxide, linalylacetate). The coefficients for the polar substances (cis-3-hexenol, phenyl ethyl alcohol) show comparatively no difference. The K values for non-polar substances partitioned between milk and LDPE are comparable with values obtained for partitioning into 50% ethanol. Despite the relatively low fat content of whole milk (3.5 %), milk behaves quite differently from wine (Kozinowski, 1989). While wine represents a real aqueous solution whose behavior is determined by its water content, milk is not only aqueous but also a fat containing food which, because of its aqueous... 

In conclusion it must be emphasized here that the values of partition coefficients of permeating substances cover a range of more than 9 orders of magnitude (10 2 to 107) dependent on their structure and the polarity of the filled product and packaging material (e.g. polyolefins/water) and this is only for a single polymer (e.g. LDPE). This means that in practice, the importance of the partition coefficient in the permeation of organic compounds is often not given the attention it deserves. 

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