Initiation of biosynthesis in cis polyisoprenes

Tanaka, Yasuyuki; Kawahara, Seiichi; Aik-Hwee, Eng; Shiba, Ken-ichi; Ohya, Norimasa

doi:10.1016/0031-9422(95)00981-c

Cited by 42 publications

(14 citation statements)

References 24 publications

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“…On the other hand, NR does have a formal steric structure, has a high molecular weight, and is readily available. [7][8][9] The NR used for vehicle tire and for various other rubber products is mostly ''mainframe'' rubber material. NR exhibits good elasticity and mechanical strength but has poor heat resistance and low resistance to weathering and chemical reagents.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and properties of hydrogenated natural rubber

Inoue

Nishio

2006

J of Applied Polymer Sci

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A series of hydrogenated natural rubbers, HNRs, were prepared by homogenous hydrogenation using H 2 gas with a rhodium catalyst (chlorotris(triphenylphosphine)rhodium) in toluene. The HNRs were linear polymers with molecular weights greater than 800,000. These rubbers were vulcanized using sulfur and peroxide compounds. Vulcanized 100% HNR has a low glass transition temperature (T g ¼ À438C) and excellent abrasion resistance, and is resistant to oxidation and ozonolysis ageing.

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Section: Introductionmentioning

confidence: 99%

Synthesis and properties of hydrogenated natural rubber

Inoue

Nishio

2006

J of Applied Polymer Sci

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“…No entanto deve-se lembrar que, embora os compósitos com negro de fumo sejam mais condutivos, o seu processamento é mais difícil em relação aos compostos contendo polímero condutor. Estes resultados de processamento e condutividade elétrica são bastante importantes, principalmente se comparados com os dos compósitos condutivos de negro de fumo com algumas borrachas [16][17][18][19][20][21] e de algumas blendas condutivas de polianilina e polipirrol [22][23][24][25] . No primeiro caso necessita-se de uma grande quantidade de negro de fumo para se obter uma condutividade elétrica razoável, causando-se prejuízos nas propriedades mecânicas e dificuldades de processamento.…”

Section: Caracterização Elétricaunclassified

Compósitos de Borracha Natural com Compostos Condutivos à Base de Negro de Fumo e Polímero Condutor

et al. 2001

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Neste trabalho foram desenvolvidos compósitos condutores elétricos de borracha natural contendo negro de fumo e compostos condutivos baseados em polímeros condutores (Eenomer®). Os compósitos foram processados a quente num reômetro de torque HAAKE e moldados por prensagem. Foram obtidas placas homogêneas, flexíveis e com ótimo acabamento superficial. Os compósitos foram analisados pelas medidas de torque no processamento, medidas de condutividade elétrica, análise termogravimétrica (TGA), calorimetria diferencial de varredura (DSC) e ensaios de tração. Estes compósitos apresentaram valores de condutividade elétrica entre 10-7 a 10-1 S/cm, dependendo do tipo de negro de fumo ou composto condutivo utilizado e da quantidade destes no compósito. A análise térmica demonstrou que os compósitos são termicamente estáveis até cerca de 300°C. Os compostos condutivos atuam como reforço para a borracha natural melhorando suas propriedades mecânicas sem perder significativamente sua flexibilidade.

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“…As a consequence, great industrial and scientific attention is paid to non-rubbers structure and their primary importance on natural rubber structure to construct the magical mechanical performance [16], such as high strength of raw rubber (green strength), shape retention, high tensile strength, high crack growth resistance and minimal heat built up in the vulcanized state. Tanaka, Y [17,18] first proposed that cispolyisoprenes obtained from H. brasiliensis and Parthenium aryentatum consist of more than 5000 isoprene units and that there are trans-isoprene units per rubber chain. Tanaka, Y [17,18] first proposed that cispolyisoprenes obtained from H. brasiliensis and Parthenium aryentatum consist of more than 5000 isoprene units and that there are trans-isoprene units per rubber chain.…”

Section: Introductionmentioning

confidence: 99%

A rheological study on non-rubber component networks in natural rubber

Huang

Luo

et al. 2015

RSC Adv.

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Non-rubber components, mainly indicating phospholipid and protein, were separately removed from natural rubber to individually study their effect on structure and properties of the rubber. Fourier Transform Infrared Spectroscopy (FTIR) and 1 H nuclear magnetic resonance ( 1 H NMR) were applied to characterize the chemical structure and the non-rubber component residual. Rheology study and stress relaxation measurement were adopted to study the role non-rubbers played in natural networks. Rheological study of natural rubber (NR) and deproteinized natural rubber (DPNR) exhibited similar dynamic modulus at 170 o C. The lack of superposition in van Gurp Palmen (vGP) curves at different temperature for NR and DPNR, together with the shape of vGP curves proved that long chain branching was mainly constructed by phospholipid. Stress relaxation measurement at room temperature was fitted with Maxwell model and showed that NR relaxation curve underwent a quick decrease and then come to 58% equilibrium stress retention, about 3 times higher than that of DPNR, indicating that protein in NR contributed to the network structure at room temperature. Combined the chemical with molecule dynamic study, the interaction between protein and phospholipid in non-rubber component network was proposed.

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Initiation of biosynthesis in cis polyisoprenes

Cited by 42 publications

References 24 publications

Synthesis and properties of hydrogenated natural rubber

Synthesis and properties of hydrogenated natural rubber

Compósitos de Borracha Natural com Compostos Condutivos à Base de Negro de Fumo e Polímero Condutor

A rheological study on non-rubber component networks in natural rubber

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