Oraphin ChaikumpollertYoshimasa YamamotoKrisda SuchivaPhan Trung NghiaSeiichi KawaharaNagaoka University of TechnologyMahidol UniversityThailand National Metal and Materials Technology CenterHanoi University of Science and Technology2018-06-112018-06-112012-04-01Polymers for Advanced Technologies. Vol.23, No.4 (2012), 825-82810991581104271472-s2.0-84858299195https://repository.li.mahidol.ac.th/handle/20.500.14594/14379Protein-free natural rubber was prepared by incubation of natural rubber latex with urea and polar organic solvent in the presence of surfactant. Effect of the polar organic solvent on the removal of the proteins was investigated with respect to chemical affinity and concentration of the solvents. Under a suitable condition, nitrogen content of the deproteinized natural rubber (DPNR) was 0.000wt%, which was less than that of natural rubber deproteinized with proteolytic enzyme or urea in the presence of surfactant. The removal of all proteins from natural rubber was proved through FT-IR spectroscopy. Changes in morphology of the DPNR were also investigated by transmission electron microscopy. © 2011 John Wiley & Sons, Ltd.Mahidol UniversityMaterials ScienceArticleSCOPUS10.1002/pat.1965