Raman structural study of random copolymers of ethylene with 1-hexene

Zavgorodnev, Yu V; Prokhorov, K. A.; Новокшонова, Л. А.; Ushakova, T. M.; Starchak, E. E.; Крашенинников, В. Г.; Nikolaeva, G. Yu.; Sagitova, E.A.; Пашинин, П. П.; Guseva, M. A.; Donfack, Patrice; Kammer, Bernd von der; Materny, Arnulf

doi:10.1134/s1054660x12040305

Cited by 19 publications

(25 citation statements)

References 40 publications

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“…Raman spectroscopic investigations of the prepared in this work nascent polymer products revealed that the increase of copolymer fraction content in the RBs leads to the decrease of trans‐conformers in the material amorphous phase. In distinction from the net UHMWPE, the amorphous phase of RBs for the most part consists of gauche‐conformers …”

Section: Resultsmentioning

confidence: 99%

Influence of copolymer fraction composition in ultrahigh molecular weight polyethylene blends with ethylene/1‐hexene copolymers on material physical and tensile properties

Ushakova

Starchak

Крашенинников

et al. 2013

J of Applied Polymer Sci

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The reactor blends (RBs) with bimodal molecular weight distribution on the base of ultrahigh molecular weight polyethylene (UHMWPE) and low molecular weight random ethylene/1-hexene copolymers (CEH) were synthesized by two-step processes including ethylene polymerization followed by ethylene/1-hexene copolymerization over rac-(CH 3 ) 2 Si(Ind) 2 ZrCl 2 /methylaluminoxane catalyst. The four series of blends differed in a composition of copolymer fraction that was varied in a wide range (from 3.0 to 37.0 mol % of 1-hexene). The differential scanning calorimetric study shows the double melting behavior of the net semicrystalline CEHs, which can be attributed to intramolecular heterogeneity in chain branch distribution. The introduction of CEHs leads to the modification of nascent RB crystalline and amorphous phases. Physical and tensile properties as well as melting indexes of the materials depend not only on the percentage of copolymer fraction that varied from 6.9 to 35.8 wt % but also on its composition. The increase of copolymer fraction with high content of 1-hexene (11.0 mol %) in the blends leads to the change of the character of stress-strain curves; the materials behave as elastomers. Controlled regulation of copolymer fraction characteristics in the synthesis yields RBs combining the enough high strength, good plastic properties with enhanced melting indexes as compared with the net UHMWPE.

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Section: Resultsmentioning

confidence: 99%

Influence of copolymer fraction composition in ultrahigh molecular weight polyethylene blends with ethylene/1‐hexene copolymers on material physical and tensile properties

Ushakova

Starchak

Крашенинников

et al. 2013

J of Applied Polymer Sci

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“…To probe the crystal morphology of all these polymers and gain a better understanding of the transformation from being crystalline to amorphous to crystalline state as the branch frequency increases, a detailed infrared (IR) analysis was carried out. Although the X‐ray diffraction techniques provide direct information about the crystal structure, IR spectroscopy can give an idea of the crystal structure and its order for the copolymers . Tashiro et al .…”

Section: Methodsmentioning

confidence: 99%

Long‐chain branched random polyethylene via acyclic diene metathesis (ADMET) copolymerization

Rojas

Wagener

2018

J. Polym. Sci. Part A: Polym. Chem.

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Five types of ethylene/α‐alkene model copolymers containing 21‐carbon alkyl branches have been synthesized via acyclic diene metathesis (ADMET) copolymerization. The overall branch content is controlled by varying the feedstock ratio of the long‐chain branched symmetrical α, ω‐diene and 1,9‐decadiene. Well‐defined melting transitions are present at low branch incorporation, followed by the broadening of the endotherms as the branch contents increase. However, instead of making the material amorphous, further increasing of the branch contents leads to the retrieval of the semi‐crystalline material creating a new crystalline domain, branches that co‐crystallize. Detailed IR spectra analyses suggest a crystal morphology transformation from orthorhombic to hexagonal phase as the branch content increases in these polymers. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018

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“…The longitudinal acoustic modes below 500 cm −1 have been used to probe crystal thickness or order state of the amorphous phase whereas skeletal modes between 500 and 1,500 cm −1 have been useful to quantify crystal content or chain orientation . Recently, changes in the Raman spectral profiles of polyethylene chains due to the incorporation of comonomers such as 1‐hexene, 1‐octene, or propylene have been analyzed, with particular focus in the 500‐ to 1,500‐cm −1 region . However, the complex spectral patterns composed of several superposed peaks have precluded attempts to establish a reliable method for comonomer quantification .…”

Section: Introductionmentioning

confidence: 99%

“…Recently, changes in the Raman spectral profiles of polyethylene chains due to the incorporation of comonomers such as 1‐hexene, 1‐octene, or propylene have been analyzed, with particular focus in the 500‐ to 1,500‐cm −1 region . However, the complex spectral patterns composed of several superposed peaks have precluded attempts to establish a reliable method for comonomer quantification . A spectral region much less explored in polymer analytics is that between 2,800 and 3,100 cm −1 , where C―H stretching modes arise.…”

Section: Introductionmentioning

confidence: 99%

Characterizing chemical composition of polyolefin‐based copolymers from spectral features in the C―H stretching region

Tomba

Silva

Genga

et al. 2018

J Raman Spectroscopy

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The comonomer content of a series of commercial ethylene–octene (Engage®, Infuse®), ethylene–butene (Engage), and ethylene–propylene (Versify®, Nordel®) copolymers is investigated using the Raman spectroscopy. The analysis relies upon the different content of methyl, methylene, and methine groups of each copolymer and focuses on the spectral features of the C―H stretching region. Raman spectra of a series of molecules with well‐defined content of methyl, methylene, and methine groups (alkanes and well‐defined polymer chains) are first addressed to rationalize the complex spectral features arising from different stretching modes, their Fermi resonance, and the different molecular conformations. Results are interpreted on the base of recent work on the topic. A curve‐fitting procedure is proposed to resolve contributions arising from CH2 and CH3 groups. The sum of intensity of bands at 2,855 and 2,865 cm−1 (symmetric C―H stretching and Fermi resonance) correlates linearly with CH2 content whereas that at 2,880 cm−1 (symmetric C―H stretching) does with CH3 content. With that base, Raman spectra of ethylene‐based copolymers are analyzed to quantify comonomer content. Results are compared with independent results from 13C nuclear magnetic resonance analysis with good agreement between the methods. Overall, it highlights the importance of Raman spectroscopy as versatile tool for process monitoring, quality control, or sample identification not only at academics but also in industrial environments.

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Raman structural study of random copolymers of ethylene with 1-hexene

Cited by 19 publications

References 40 publications

Influence of copolymer fraction composition in ultrahigh molecular weight polyethylene blends with ethylene/1‐hexene copolymers on material physical and tensile properties

Influence of copolymer fraction composition in ultrahigh molecular weight polyethylene blends with ethylene/1‐hexene copolymers on material physical and tensile properties

Long‐chain branched random polyethylene via acyclic diene metathesis (ADMET) copolymerization

Characterizing chemical composition of polyolefin‐based copolymers from spectral features in the C―H stretching region

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