1. Departamento de Química, Universidad del Valle, AA 25360, Cali, Colombia
2. Center for Macromolecular Science and Engineering, The George and Josephine Butler Polymer Research Laboratory, Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200
3. Petrochemicals Research Laboratory, Sumitomo Chemical Company, Kitasode 2-1, Sodegaura, Chiba 299-0295, Japan