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This article uses both cross-sectional and longitudinal methods to evaluate the national industrial relations systems of 30 Organisation for Economic Co-operation and Development (OECD) countries from 1993 to 2005. We adopt a pluralistic view of industrial relations that gives equal weight to efficiency and equity, along with a general systems model consisting of input, process and output. We rank each country in terms of a combined score of efficiency and equity. We find that the 30 OECD countries can be separated into three distinct groups (high on both equity and efficiency; high on efficiency but low on equity; moderate on equity and low on efficiency), and that these groups exhibit considerable stability over time.

Nanocomposites of thermoplastic polyurethanes (TPUs), multiwalled carbon nanotubes (MWCNTs) and clays were prepared via melt processing using polyether- and polyester-based TPUs, MWCNTs, and organically modified nanoclays (Cloisite C30B and C25A). Coaddition of clays and MWCNTs to TPU nanocomposites increased their electrical conductivities above those without any clay. Nanoclay alone is shown to produce no effect on electrical conductivity. TEM results show that the coaddition of nanoclay affects the nanocomposite morphology by changing the MWCNT distribution. Clay C25A and MWCNTs were observed to form network structures in the nanocomposites, resulting in improved electrical conduction. Interaction between MWCNTs and clays as well as an increase in nanocomposite viscosity caused by the coaddition of clays may influence the morphology change. Most of the nanocomposites containing both MWCNTs and clay exhibited higher dielectric constants, indicating higher electrical conductivities. Tensile properties investigations confirmed the reinforcing effects of the MWCNTs and clays. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Effect of different solvents on the clay dispersion and the final properties of the thermoplastic polyurethanes (TPUs)/clay nanocomposites prepared via solution mixing was studied. The polyether- and polyester-based TPUs were used along with organically modified clays (C30B, C25A, and C15A) and the pristine montmorillonite (PM). Dimethylacetamide (DMAc) and tetrahydrofuran (THF) were used as solvents for solution mixing. Nanocomposites containing C30B prepared from DMAc solution showed the better clay dispersion than the ones from THF solution, while THF gave the better dispersion of clays for nanocomposites containing C15A. Morphologies of the nanocomposites were observed to be determined not only by the state of clay dispersion in different solvents but also by the interaction between the polymer and the specific clay. Affinity between solvents and clays becomes important when there is no specific interaction between the clay and the polymer of interest, or when the interaction between the two is rather weak. The compatibility between clays and polymers becomes dominating if there exists a specific interaction between the two. FTIR analysis was conducted to study the interactions involved in the nanocomposites. Dynamic mechanical properties measurement was also carried out to see the effect of solvents. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008