Rhodium complexes modified by simple trialkylphosphines can be used to carry out homogeneous hydroformylation in supercritical carbon dioxide (scCO(2)). The catalyst derived from PEt3 is more active and slightly more selective for the linear products in scCO2 than in toluene, and under the same reaction conditions [100degreesC, 40 bar of CO/H-2 (1:1)] P(OPri)(3) is also an effective ligand giving good catalyst solubility and activity. Other ligands such as PPh3, POct(3), PCy3, and P(4-C6H4But)(3) are less effective because of the low solubility of their rhodium complexes in scCO(2). P(4-C6H4SiMe3)(n) Ph3-n (n = 3 or 1) and P(OPh)(3) impart activity despite their complexes only being poorly soluble in scCO(2). Under subcritical conditions, using PEt3 as the ligand, C7-alcohols from hydrogenation of the first formed aldehydes are the main products whilst above a total pressure of 200 bar, where the solution remains supercritical (monophasic) throughout the reaction, aldehydes are obtained with 97% selectivity. High pressure IR studies in scCO(2) using PEt3 as the ligand are reported.

The resulting economic integration of industrial processes and manufacturing internationalisation lead several authors to argue that world economy is globalised. In this context, the approach to the divestment concept without an social and económical context, does not show a group of associated practices and representations. Choices and options are motivated by exogenous forces that pushes companies to determine strategies that stop capital investment on new equipment goods, or on other imaterial goods. This type of strategy is designated by "divestment". The social level of consequencies are not due to the closing down or de-localization of production units that are divesting, but can be materialised of efects that are irreversible. This means unemployment, de-skilling, labour precarization and even emergence of new forms of social exclusion in former industrialised regions.

Thin films of low density polyethylene (LDPE) and crosslinked polyethylene (XLPE) were aged under an AC electric field while kept in sodium chloride aqueous solution. After aging the samples showed water trees (localized damaged with the appearance of hydrophilic ramified structures whose size ranges from a few microns to I mm). Some of the samples suffered dielectric breakdown showing small channels (1-2 mm. diameter) crossing the film and sometimes also signs of carbonization. In order to identify the oxidation mechanisms contributing to aging, FTIR was used to analyze both unaged and aged specimens. Comparing between unaged and aged LDPE an increase in the FTIR spectrum for bands at 1720 cm(-1), 1640 cm(-1) and 1590 cm(-1) was visible for the aged samples. The first region corresponds to carbonyl groups (C=O bonds) resulting from oxidation (most probably ketones). While the second one is related to carbon double bonds formed due to chain scission. Finally the third one is due to carboxylates. For the XLPE the analysis is more difficult. Besides aging it needs to be taken into account the by-products of crosslinking that will tend also to diffuse out with time. The main effect of aging is an increase in the concentration of 1640 cm(-1) band (C=C bonds). For the water treed regions dry and wet samples were compared. In the wet ones the absorbance is larger for the 3380 cm(-1) exhibiting, as expected, water absorption in the water treed regions (hydrophilic characteristics were increased).

Thin films of low density polyethylene (LDPE) and crosslinked polyethylene (XLPE) were aged under an AC electric field while kept in sodium chloride aqueous solution. After aging the samples showed water trees (localized damaged with the appearance of hydrophilic ramified structures whose size ranges from a few microns to I mm). Some of the samples suffered dielectric breakdown showing small channels (1-2 mm. diameter) crossing the film and sometimes also signs of carbonization. In order to identify the oxidation mechanisms contributing to aging, FTIR was used to analyze both unaged and aged specimens. Comparing between unaged and aged LDPE an increase in the FTIR spectrum for bands at 1720 cm(-1), 1640 cm(-1) and 1590 cm(-1) was visible for the aged samples. The first region corresponds to carbonyl groups (C=O bonds) resulting from oxidation (most probably ketones). While the second one is related to carbon double bonds formed due to chain scission. Finally the third one is due to carboxylates. For the XLPE the analysis is more difficult. Besides aging it needs to be taken into account the by-products of crosslinking that will tend also to diffuse out with time. The main effect of aging is an increase in the concentration of 1640 cm(-1) band (C=C bonds). For the water treed regions dry and wet samples were compared. In the wet ones the absorbance is larger for the 3380 cm(-1) exhibiting, as expected, water absorption in the water treed regions (hydrophilic characteristics were increased).