Hydrogenation of cis‐1,4‐poly(isoprene) catalyzed by OsHCl(CO)(O2)(PCy3)2

The quantitative hydrogenation of cis‐1,4‐poly(isoprene) (CPIP) provides an easy entry to the alternating copolymer of ethylene–propylene, which is difficult to prepare by conventional polymerization. The homogeneous hydrogenation of CPIP, in the presence of OsHCl(CO)(O₂)(PCy₃)₂ as catalyst, has been studied by monitoring the amount of hydrogen consumed during the reaction. The final degree of olefin conversion measured by computer‐controlled gas uptake apparatus was confirmed by infrared spectroscopy and ¹H nuclear magnetic resonance analysis. Kinetic experiments for CPIP hydrogenation in toluene solvent indicate that the hydrogenation rate is first order with respect to catalyst and carbon–carbon double bond concentration. A second‐order dependence on hydrogen concentration for low values and a zero‐order dependence for higher values of the hydrogen concentration was observed. The apparent activation energy for the hydrogenation of CPIP over the temperature range of 115–140°C was 109.3 kJ/mole. Mechanistic aspects of this catalytic process are discussed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 142–152, 2003     

The quantitative eco-efficiency measurement for small and medium enterprise: a case study of wooden toy industry

Eco-efficiency is a tool for the analysis of the sustainability of industries, which indicates the economic relationship and environmental impact. This research presents the development of eco-efficiency indicators for quantitative measurement of the wooden toy industry, as well as the raw material suppliers who are a part of the supply chain. The eco-efficiency of the wooden toy industry was measured by using the key indicators of the three axes of sustainable development, which are (i) economic indicator: net sale and gross margin, (ii) environmental indicator: material, energy, water consumption, waste disposal, and (iii) social indicator: frequency rate of accidents, local employment, and corporate social responsibility. Moreover, the combined eco-efficiency evaluation of the supplier and company showed that the company’s eco-efficiency has likely increased during 2 years of observation, while the eco-efficiency of the supplier-company combination has decreased. The evaluation of socio-eco-efficiency results showed that the company has acquired a socially supportive management system at the company level, community level, and social level. This research can contribute to the improvement of the resource and process efficiencies in economic, environmental, and social dimensions. It can also provide a basic framework on eco-efficiency evaluation for the small and medium enterprises in Thailand, which will feed into policy and strategic development.     

Hydrogenation of synthetic cis‐1,4‐polyisoprene and natural rubber catalyzed by [Ir(COD)py(PCy3)]PF6

In the presence of chlorinated solvents, the catalytic complex [Ir(COD)py(PCy₃)]PF₆ (where COD is 1,5‐cyclooctadiene and py is pyridine) was an active catalyst for the hydrogenation of synthetic cis‐1,4‐polyisoprene and natural rubber. Detailed kinetic and mechanistic studies for homogeneous hydrogenation were carried out through the monitoring of the amount of hydrogen consumed during the reaction. The final degree of olefin conversion, measured with a computer‐controlled gas‐uptake apparatus, was confirmed by Fourier transform infrared spectroscopy and ¹H‐NMR spectroscopy. Synthetic cis‐1,4‐polyisoprene was used as a model polymer for natural rubber without impurities to study the influence of the catalyst loading, polymer concentration, hydrogen pressure, and reaction temperature with a statistical design framework. The kinetic results for the hydrogenation of both synthetic cis‐1,4‐polyisoprene and natural rubber indicated that the hydrogenation rate exhibited a first‐order dependence on the catalyst concentration and hydrogen pressure. Because of impurities inside the natural rubber, the hydrogenation of natural rubber showed an inverse behavior dependence on the rubber concentration, whereas the hydrogenation rate of synthetic rubber, that is, cis‐1,4‐polyisoprene, remained constant when the rubber concentration increased. The hydrogenation rate was also dependent on the reaction temperature. The apparent activation energies for the hydrogenation of synthetic cis‐1,4‐polyisoprene and natural rubber were evaluated to be 79.8 and 75.6 kJ/mol, respectively. The mechanistic aspects of these catalytic processes were discussed on the basis of observed kinetic results. The addition of some acids showed an effect on the hydrogenation rate of both rubbers. The thermal properties of hydrogenated rubber samples were determined and indicated that hydrogenation increased the thermal stability of the hydrogenated rubber but did not affect the inherent glass‐transition temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4219–4233, 2006     

Eco-efficiency assessment of pulp and paper industry in Myanmar

This paper presents the eco-efficiency assessment of the pulp and paper industry in Myanmar by using the key indicators such as raw material consumption, energy consumption, total waste output, water consumption, and CO₂ emissions. The study was carried out by using quantitative methods for data analysis of the production, consumptions and emissions from fiscal year 2001–2005. The results revealed that the level of economic and environmental performance using the eco-efficiency ratio for each fiscal year has decreased since year 2002, and factory tried to increase the level of eco-efficiency again in year 2005. There was the positive aspect that factory could optimize the waste utilization by transferring lime mud to the cement factory in the last two fiscal years. This analysis showed the root causes that led to the losses of material, energy and water consumption and discussed how to conserve those utilities.