Experimentally- and theoretically-evaluated ultimate 3-dimensional elastic constants of trans-1,4-polyisoprene α and β crystalline forms on the basis of the newly-refined crystal structure information

Ratri, Paramita Jaya; Tashiro, Kohji; Iguchi, Masatoshi

doi:10.1016/j.polymer.2012.06.003

Cited by 29 publications

(21 citation statements)

References 25 publications

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“…The synthetic TPI sample with 99% trans content was purchased from Polysciences Inc. (Warrington, PA, USA). As described in a previous study, 29 and the unoriented pure b-form sample was prepared by quenching the melt at liquid N 2 temperature followed by slowly heating to room temperature.…”

Section: Experimental Procedures Samplesmentioning

confidence: 99%

Phase-transition behavior of a crystalline polymer near the melting point: case studies of the ferroelectric phase transition of poly(vinylidene fluoride) and the β-to-α transition of trans-1,4-polyisoprene

Ratri

Tashiro

2013

Polym J

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Many crystalline polymers exhibit phase transitions between the low-and high-temperature phases during the heating process. Sometimes, however, the temperature-dependent measurement of the X-ray diffraction peaks and vibrational spectra leads us to the incorrect conclusion that these two phases transform in a direct solid-to-solid transition mode instead of the melt and recrystallization process. As a reliable method to confirm the transition behavior just below the melting region, we have developed a temperature-jump cell system, with which a time-dependent measurement of the X-ray diffraction peaks (and Fourier-transform infrared spectra) is performed in the rapidly changing temperature process from the low-to the hightemperature phase. This method was applied to two types of polymers and revealed that (i) the high-temperature phase transition of poly(vinylidene fluoride) is not a direct ferroelectric transition between the ferroelectric and paraelectric phases, as proposed in our previous studies (Polymer (1983), Polym. Bull. (1983)), but a melt of the ferroelectric phase (form I) followed by the recrystallization into the nonpolar crystalline phase (form III or V) and (ii) the b-to-a phase transition of trans-1,4-polyisoprene had been also controversial for many years but it was revealed to occur via a melt-recrystallization mechanism.

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Section: Experimental Procedures Samplesmentioning

confidence: 99%

Phase-transition behavior of a crystalline polymer near the melting point: case studies of the ferroelectric phase transition of poly(vinylidene fluoride) and the β-to-α transition of trans-1,4-polyisoprene

Ratri

Tashiro

2013

Polym J

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“…Fig. 3a indicates the presence of both α and β forms, as represented by two distinguished peaks (95.68 J/g) at Tendo= 64.92 ºC and Tendo= 60.67 ºC, respectively, with predominantly α-form [26,35,40]. Whereas in Fig.…”

Section: Characterization Of the Chicle Gum (Manilkara Zapota) From Ymentioning

confidence: 91%

“…The CPI shows a broad halo at 2θ= 20º which is the signature of the amorphous nature of the sample, whereas TPI is partially crystalline. The interplanar spacing has been calculated using the Bragg's law from which two crystalline phases, namely the α and β polymorphic forms were identified [33,40]. The α-form has a monoclinic unit cell with two chains, each containing two repeat units (d= 7.82, 5.52, 5.09 The chicle gum was subjected to thermogravimetric analysis.…”

Section: Characterization Of the Chicle Gum (Manilkara Zapota) From Ymentioning

confidence: 99%

Chicle Gum from sapodilla (Manilkara zapota) as a Renewable Resource for Metathesis Transformations

2018

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In this study, we report on for the first time the self-metathesis of the chicle gum and cross-metathesis of the chicle gum rubber isolated from the gummy latex of sapodilla (Manilkara zapota) with orange oil, β-pinene and, methyl methacrylate using the Ru-alkylidenes Hoveyda-Grubbs and Grubbs second generation catalysts. There were obtained terpene- and ester-terminated oligoisoprenes, with good yields and selectivities. The present results are a promising starting point for the application of this underexploited renewable resource as a new feedstock for metathesis transformations.

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“…The high regularity and purity of EUG cause it a crystalline material, with hard plasticlike appearance. 17,18 Therefore, almost no EUG was used alone in the rubber industry. In most cases, EUG was blended with other materials, such as cispolyisoprene, [19][20][21][22] chlorobutadiene rubber, 23 cellulose, 24,25 poly(ε-caprolactone), 26 polylactide, 27 polypropylene, 28 to improve the properties of composites or was used to prepare shape memory materials.…”

Section: Introductionmentioning

confidence: 99%

A high toughness elastomer based on naturalEucommia ulmoidesgum

Zhao

et al. 2020

J of Applied Polymer Sci

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Eucommia ulmoides gum (EUG) is a kind of bio-based polymer with similar structure to natural rubber (NR). However, it behaves as hard plastic at room temperature due to crystallization, which makes it not as widely used as NR. Herein, a new bio-based elastomer (HEUG) was prepared by rhodiumcatalyzed hydrogenation of EUG for the first time. 1 H-NMR and 13 C-NMR spectroscopy confirmed the structure of HEUG, and wide angle X-ray diffraction, polarizing light microscopy showed that the crystal was gradually destroyed in the hydrogenation process, finding that when the degree of hydrogenation is more than 16.5%, HEUG transformed from plastic to elastomer at room temperature. Besides, the Synchrotron Radiation experiment showed that HEUG with hydrogenation of 85.9% could be self-reinforced by strain-induced crystallization during stretching, which make it has excellent tensile strength and toughness (21.4 MPa and 68.1 MJ m −3 , respectively). This new bio-based elastomer has the potential to replace NR and has a wide application prospect in rubber industry.

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Experimentally- and theoretically-evaluated ultimate 3-dimensional elastic constants of trans-1,4-polyisoprene α and β crystalline forms on the basis of the newly-refined crystal structure information

Cited by 29 publications

References 25 publications

Phase-transition behavior of a crystalline polymer near the melting point: case studies of the ferroelectric phase transition of poly(vinylidene fluoride) and the β-to-α transition of trans-1,4-polyisoprene

Phase-transition behavior of a crystalline polymer near the melting point: case studies of the ferroelectric phase transition of poly(vinylidene fluoride) and the β-to-α transition of trans-1,4-polyisoprene

Chicle Gum from sapodilla (Manilkara zapota) as a Renewable Resource for Metathesis Transformations

A high toughness elastomer based on naturalEucommia ulmoidesgum

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