Removal of proteins from natural rubber with urea

Kawahara, Seiichi; Klinklai, Warunee; Kawakubo, Hirofumi; Isono, Yoshinobu

doi:10.1002/pat.465

Cited by 95 publications

(82 citation statements)

References 8 publications

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“…Another common chemical used in latex deproteinsation is sodium dodecyl sulphate (SDS) which is an anionic surfactant [CH 3 (CH 2 ) 11 OSO 3 Na]. Owing to the synergistic effect between both chemicals, effective proteins removal was described [14]. It is proposed in urea-SDS protein denaturation mechanism (Figure 1), urea may unfolded the proteins while SDS binds onto the surface of unfolded proteins and imparts negative charges, resulting in the protein to have higher net negative charge compared to its previous state.…”

Section: -2506mentioning

confidence: 99%

Zeta Potential and Environmental Scanning Electron Microscopy Analysis in Deproteinisation of Natural Rubber Latex

Abdullah¹

2016

MJAS

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This paper describes the effect of protein denaturants namely, urea and sodium dodecyl sulphate (SDS) in the deproteinisation of high ammonia natural rubber latex (HA-NRL). It had been shown that latex proteins were reduced more in the presence of urea alone (48%) than in the presence of SDS (18%). The synergistic effect when both urea and SDS were used in the latex deproteinisation attributed to the higher protein removal efficacy (55%). Higher zeta potential value was observed when only SDS was used, suggesting higher colloidal stability. Environmental Scanning Electron Microscopy (ESEM) revealed that without SDS, the use of urea single-handedly in the deproteinisation process promoted aggregation of latex particles, possibly due to the dismissal of latex proteins which helped to stabilise latex colloidal. Thus, it is most likely that urea serves as a protein unfolding agent during latex deproteinisation process, while SDS functions as a latex stabiliser with no significant effects on latex proteins discharge.Keywords: urea, sodium dodecyl sulphate, deproteinisation, zeta potential, environmental scanning electron microscopy Abstrak Kertas kerja ini menghuraikan kesan bahan-bahan pengubah sifat protein iaitu urea dan natrium dodekil sulfat (NDS) dalam penyahprotein lateks getah asli tinggi ammonia (HA-NRL). Ia telah menunjukkan bahawa protein lateks lebih banyak dikurangkan dengan kehadiran urea sahaja (48%) berbanding dengan kehadiran NDS sahaja (18%). Keberkesanan penyingkiran protein yang lebih tinggi (55%) mungkin telah disebabkan oleh kesan sinergi apabila kedua-dua urea dan NDS digunakan di dalam penyahprotein lateks. Nilai keupayaan zeta yang tinggi diperhatikan apabila hanya NDS digunakan, menunjukkan kestabilan koloid yang lebih tinggi. Pengimbas Persekitaran Mikroskopi Elektron (ESEM) menunjukkan bahawa tanpa NDS, penggunaan hanya urea dalam proses penyahprotein menyumbang kepada kesan pengagregatan zarah lateks, kemungkinan disebabkan oleh penyingkiran protein lateks yang membantu dalam kestabilan koloid lateks. Oleh yang demikian, besar kemungkinan fungsi utama urea semasa proses penyahprotein lateks adalah sebagai ejen pembuka protein manakala NDS berfungsi sebagai penstabil lateks tanpa kesan ketara pada penyingkiran protein lateks.

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Section: -2506mentioning

confidence: 99%

Zeta Potential and Environmental Scanning Electron Microscopy Analysis in Deproteinisation of Natural Rubber Latex

Abdullah¹

2016

MJAS

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“…Deproteinized natural rubber (DPNR) was prepared by incubation of the latex with 0.2 wt% urea and 1 wt% SDS at a reaction temperature of 30 o C for 60 min according to the work of Kawahara et al [11]. The crumb rubber was recovered by centrifugation followed by coagulation with methanol and dried to a constant weight in a vacuum oven.…”

Section: Preparation Of Deproteinized Natural Rubber and Htlnrmentioning

confidence: 99%

Synthesis of hydroxyl terminated liquid natural rubber by oxidative depolymerization of deproteinized natural rubber

Giang

Thao

Huong

et al. 2016

JST

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Hydroxyl terminated liquid natural rubber (HTLNR) was prepared by the depolymerization of deproteinized natural rubber (DPNR) in mixture of toluene and water at 60 o C for 24 hours in the presence of ammonium persulfate as an initiator and tetrahydrofuran (THF) as a homogenizing agent. GPC analysis revealed that the number-average molecular weight (M n ) and weight-average molecular weight (M w ) of HTLNR were found to be 4.334×10 3 g/mol and 11.702×10 3 g/mol, respectively, with polydispersity index (PDI) of 2.7. The chemical structure of HTLNR was determined by FTIR and 1 H-NMR and 13 C-NMR spectroscopic analysis. Based on the analytical data the mechanism of depolymerization and hydroxylation of NR to form HTNR was also suggested.Keywords: deproteinized natural rubber (DPNR), hydroxyl terminated liquid natural rubber (HTLNR), depolymerization of natural rubber, oxidative degradation.

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“…Besides, protein also causes formation of gel or a branched network in NR. 17,18 Consequently, it is very crucial to remove proteins from the NR latex before carrying out the chemical modification.…”

Section: Introductionmentioning

confidence: 99%

“…19 However, it is time consuming, that is more than 24 h of the incubation, and the remaining proteins, peptides, or amino acid sequences can cause intraoperative anaphylactic reactions of hypersensitive patients of allergy. 18 We established the novel procedure for removal of protein from NR by incubating NR latex with urea followed by three times of washing by centrigufation. 18 In this method, urea was used as an effective denaturing agent, resulting in the decrease of nitrogen content of NR from 0.38 to 0.02%, just for about one hour of incubation.…”

Section: Introductionmentioning

confidence: 99%

“…18 We established the novel procedure for removal of protein from NR by incubating NR latex with urea followed by three times of washing by centrigufation. 18 In this method, urea was used as an effective denaturing agent, resulting in the decrease of nitrogen content of NR from 0.38 to 0.02%, just for about one hour of incubation. 20 Redox initiator is composed of two components.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Modification of Vietnam Natural Rubber via Graft Copolymerization with Styrene

Dung¹,

Nhàn²,

Thương³

et al. 2016

J. Braz. Chem. Soc.

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Graft copolymerization of styrene onto deproteinized natural rubber (DPNR) using tert-butyl hydroperoxide (TBHPO) and tetraethylene pentamine (TEPA) as redox initiator have been investigated. The effects of initiator and monomer concentration on conversion and grafting efficiency were studied. The dynamic mechanical and thermal properties of the graft copolymer were investigated over the wide range of temperatures. It is shown that a high value of storage modulus for the graft copolymer, which was about 25 times as high as that of DPNR, was achieved. The graft copolymer (DPNR-graft-PS) showed the outstanding tensile strength and stable thermal properties. These enhancements were attributed to the interaction between NR and polystyrene as a result of the graft copolymerization. Morphology observation by transmission electron micrograph (TEM) revealed that the core-shell arrangement of the DPNR-graft-PS with about 30 nm in thickness of polystyrene nano-layer was achieved.

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Removal of proteins from natural rubber with urea

Cited by 95 publications

References 8 publications

Zeta Potential and Environmental Scanning Electron Microscopy Analysis in Deproteinisation of Natural Rubber Latex

Zeta Potential and Environmental Scanning Electron Microscopy Analysis in Deproteinisation of Natural Rubber Latex

Synthesis of hydroxyl terminated liquid natural rubber by oxidative depolymerization of deproteinized natural rubber

Modification of Vietnam Natural Rubber via Graft Copolymerization with Styrene

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