Polymorphism analysis of trans-1,4-polyisoprene during melt-recrystallization

Nie, Huarong; Ren, Huicheng; Han, Xiao; He, Aihua

doi:10.1016/j.polymertesting.2019.106120

Cited by 7 publications

(5 citation statements)

References 26 publications

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“…This indicates that the crystallized i PB inhibited the crystallization of TPI. The melting temperature regions at 44°C to 52°C represent the Tm of α form and β form crystal of TPI phase, 47 and melting temperature regions at 117°C represent the melting peak of i PB Form II 48 . T m of i PB phase in the as‐obtained alloys is higher than that of pure i PB, which means the perfection of crystallinity of i PB phase in alloys is higher than pure i PB.…”

Section: Resultsmentioning

confidence: 99%

In situ synthesis of novel trans‐1, 4‐polyisoprene/isotactic polybutene reactor blends with multi‐component structure

Shao,

Xia,

Wang

et al. 2024

Polymer Engineering & Sci

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In this paper, a series of novel trans‐1, 4‐polyisoprene/isotactic polybutene (TPI/iPB) in‐reactor blends were synthesized by isoprene and butene sequential two‐stage polymerization technology with spherical TiCl4/MgCl2 type Ziegler‐Natta catalyst. The components, structures, and properties of the as‐obtained TPI/iPB reactor blends were characterized by gel permeation chromatography, Fourier transform Infrared spectroscopy, and differential scanning calorimetry. The active trans‐1, 4‐polyisoprene (TPI) particles obtained in the initial isoprene polymerization by the Z‐N catalyst can be acted as microreactors to initiate butene polymerization subsequently. The TPI/iPB reactor blends with varied components were in situ synthesized within the reactor. The preparative‐temperature rising elution fractionation (p‐TREF) technique was used to fractionate the TPI/iPB reactor blends based on the elution temperature ranged from −40°C to 90°C. The weight distribution and microstructure of each fraction were investigated. The reactor blends are composed of crystallizable high trans‐1, 4‐uint polyisoprene obtained from the first‐stage isoprene polymerization, high isotactic polybutene obtained from the second‐stage butene polymerization and TPI‐b‐iPB block copolymer with different sequence structure obtained from the initial time of the second stage. This work is expected to propose the possible polymerizations of a‐olefins and conjugated dienes by using heterogeneous Ziegler‐Natta catalyst and provide a kind of novel rubber/plastic reactor blend materials.Highlights The first synthesis of the trans‐1, 4‐polyisoprene/isotactic polybutene reactor blends. p‐TREF technique was used to analyze the composition of TPI/iPB reactor blends. Detailed structure characterization of the fractions including GPC and NMR TPI‐b‐iPB block copolymer can be obtained through the sequential polymerization. Rubber/plastic reactor blend materials were fabricated by the Z‐N catalyst.

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Section: Resultsmentioning

confidence: 99%

In situ synthesis of novel trans‐1, 4‐polyisoprene/isotactic polybutene reactor blends with multi‐component structure

Shao,

Xia,

Wang

et al. 2024

Polymer Engineering & Sci

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“…23,24 Notably, the diffraction peak at 22.7° displayed a low intensity while the diffraction peaks at 18.7° and 22.7° showed a relatively high intensity among all NBR/EUG composites, which indicated that most of the EUG crystals in NBR/EUG composites were β-form crystals. 25,26 Different temperatures facilitated the formation of α and β crystals during the isothermal crystallization of EUG, in which α crystal displayed a thermodynamic stable form and β crystal showed a metastable form. Thus, β crystals were produced easily at a fast cooling rate during the non-isothermal crystallization of EUG.…”

Section: Resultsmentioning

confidence: 99%

“…The appearance of these diffraction peaks was attributed to the existing crystals of EUG (containing aand b-form crystalline structures) in NBR matrix, in which the peak of the a-form crystalline structure of EUG was at 22.7 and the peaks of the b-form crystalline structure of EUG were at 18.7 and 22.7 23,24. Notably, the diffraction peak at 22.7 displayed a low intensity while the diffraction peaks at 18.7 and 22.7 showed a relatively high intensity among all NBR/EUG composites, which indicated that most of the EUG crystals in NBR/EUG composites were b-form crystals 25,26. Different temperatures facilitated the formation of a and b crystals during the isothermal crystallization of EUG, in which a crystal displayed a thermodynamic stable form and b crystal showed a metastable form.…”

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confidence: 91%

Development of nitrile rubber/eucommia ulmoides gum composites for controllable dynamic damping and sound absorption performance

et al. 2022

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“…However, the α-type crystallization peak of EUG was mainly at 2θ = 26.6°, while no crystallization peak appeared at about 2θ = 26.6° (as shown in Figure 4 b) [ 31 , 32 ], proving that the crystal type of EUG in various MPU/EUG composites is mainly β-type crystals. In reality, the forming of α-type crystals was not only related to the crystallization temperature but was also affected by the heating rate, so the forming conditions of α-type crystals were stricter than that of β-type crystals [ 33 , 34 ]. In contrast, the crystallization temperature of β-type crystals was relatively low and its forming conditions were simple [ 33 , 35 ]; hence, the existed crystals in the MPU/EUG composites were mainly β-type crystals.…”

Section: Resultsmentioning

confidence: 99%

Fabrication of Millable Polyurethane Elastomer/Eucommia Ulmoides Rubber Composites with Superior Sound Absorption Performance

et al. 2021

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Sound absorbing materials combining millable polyurethane elastomer (MPU) and eucommia ulmoides rubber (EUG) were successfully fabricated via a physical blending process of EUG and MPU. The microstructure, crystallization performances, damping, mechanical and sound absorption properties of the prepared MPU/EUG composites were investigated systematically. The microstructure surface of various MPU/EUG composites became rough and cracked by the gradual incorporation of EUG, resulting in a deteriorated compatibility between EUG and MPU. With the increase of EUG content, the storage modulus (E’) of various MPU/EUG composites increased in a temperature range of −50 °C to 40 °C and their loss factor (tanδ) decreased significantly, including a reduction of the tanδ of MPU/EUG (70/30) composites from 0.79 to 0.64. Specifically, the addition of EUG sharply improved the sound absorption performances of various MPU/EUG composites in a frequency range of 4.5 kHz–8 kHz. Compared with that of pure MPU, the sound absorption coefficient of the MPU/EUG (70/30) composite increased 52.2% at a pressure of 0.1 MPa and 16.8% at a pressure of 4 MPa, indicating its outstanding sound absorption properties.

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Polymorphism analysis of trans-1,4-polyisoprene during melt-recrystallization

Cited by 7 publications

References 26 publications

In situ synthesis of novel trans‐1, 4‐polyisoprene/isotactic polybutene reactor blends with multi‐component structure

In situ synthesis of novel trans‐1, 4‐polyisoprene/isotactic polybutene reactor blends with multi‐component structure

Development of nitrile rubber/eucommia ulmoides gum composites for controllable dynamic damping and sound absorption performance

Fabrication of Millable Polyurethane Elastomer/Eucommia Ulmoides Rubber Composites with Superior Sound Absorption Performance

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