1. Department of Rubber Technology and Polymer Science, Faculty of Science and TechnologyPrince of Songkla University Pattani Campus, Pattani 94000 Thailand
2. Indonesian Rubber Research Institute 1 Salak Rd., Bogor, West Java 16151 Indonesia
3. Synchroton Light Research Institute 111 Sirindhornwitchothai BLD., Muang, Nakhon Ratchasima 30000 Thailand