1. Department of Materials Science, Faculty of Science, Chulalongkorn University, Bangkok 10330 Thailand
2. Department of Chemistry, University of Kalyani, Kalyani, Nadia 741235 India
3. Indian Rubber Manufacturers Research Association, Thane, Maharashtra 400604 India
4. Center of Excellence on Petrochemical and Materials Technology, Chulalongkorn University, Bangkok 10330 Thailand