title: Effect of chitosan content on gel content of epoxized natural rubber grafted with chitosan in latex form.
abstract: The epoxidized natural rubber (ENR) latex-g-chitosan (ENR-g-chitosan) was prepared in latex form using potassium persulphate as an initiator. Firstly, the reduction in molecular weight of chitosan was subjected to the addition of K2S2O8 at 70 °C for 15 min. The structure of the modified chitosan was characterized by ATR-FTIR. Secondarily, the influence of chitosan contents, reaction time, and temperature and K2S2O8 concentrations on the gel content of the modified ENR was investigated. The chemical structure of the ENR-g-chitosan was confirmed by (1)H-NMR and ATR-FTIR. The ether linkage of the ENR-g-chitosan was conformed at 1154 an 1089 cm(-1) by ATR-FTIR and 3.60 ppm by (1)H-NMR. The gel content of ENR-g-chitosan at 5% chitosan showed the highest value compared with other samples. But when chitosan increased from 5% to 10% or 20%, the gel content of ENR-g-chitosan dramatically decreased. The ENR-g-chitosan showed good thermal resistance due to incorporation of chitosan. The morphology of ENR-g-chitosan particle showed the core-shell structure observed by TEM. The optimum condition of grafting ENR with chitosan was found at 65°C for 3h of reaction time, ratio of ENR/chitosan at 9:1.
authors.affiliation: Department of Materials Science and Technology and Natural Product Research Center, Faculty of Science, Prince of Songkla University, Songkhla 90110, Thailand. saadriyajan@hotmail.com
authors.forename: Sa-Ad
authors.initials: SA
authors.lastname: Riyajan
authors.forename: Wattana
authors.initials: W
authors.lastname: Sukhlaaied
mesh_terms: D048271:Chitosan / Q000138:chemical synthesis / Q000737:chemistry*; D004852:Epoxy Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D005782:Gels / Q000737:chemistry*; D007840:Latex / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D046529:Microscopy, Electron, Transmission; D017680:Potassium Compounds / Q000737:chemistry; D012408:Rubber / Q000138:chemical synthesis / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013431:Sulfates / Q000737:chemistry; D013696:Temperature; D013818:Thermogravimetry; D013997:Time Factors
chemical_list: D004852:Epoxy Compounds; D005782:Gels; D007840:Latex; D017680:Potassium Compounds; D013431:Sulfates; C009007:potassium persulfate; D012408:Rubber; D048271:Chitosan
keywords: Chemical modification; Chitosan; Grafting; Natural rubber