caa a22 4500 605466858 CHVBK 20210128100309.0 cr unu---uuuuu 210128e20150201xx s 000 0 eng 10.1007/s00397-014-0822-y doi (NATIONALLICENCE)springer-10.1007/s00397-014-0822-y The effect of molecular structure on rheological behavior of tubular LDPEs [Elektronische Daten] [Masood Khabazian Esfahani, Nadereh Ebrahimi, Ehsan Khoshbakhti] Molecular characterization of low-density polyethylene has long been faced with many challenges. Due to the lack of control over the radical polymerization under very high pressures, the low-density polyethylene (LDPE) molecular structure is very complex. This paper uses the attenuated total reflectance (ATR)-Fourier transform infrared characterization method to introduce a measuring tool to calculate the average number of branches in LDPE molecular chain. Among 28 gel permeation chromatography (GPC)-analyzed LDPEs, two GPC-identical tubular LDPE were chosen. The branching structures of the LDPEs are investigated by the van-Gurp Palmen plot. To clarify the difference between rheological behavior of LDPEs, GPC, temperature rising elution fractionation, ATR, dynamic oscillatory shear, and elongational stress growth coefficient tests were performed. It was found that high molecular weight portion of LDPE 2 has higher number of branches than LDPE 1, which is responsible for the different rheological behavior. Springer-Verlag Berlin Heidelberg, 2014 Rheology nationallicence Polyethylene nationallicence FTIR nationallicence Structure nationallicence Gel permeation chromatography nationallicence Khabazian Esfahani Masood Polymer Engineering Department, Chemical Engineering Faculty, Tarbiat Modares University, P.O. Box 14115-114, Tehran, Iran aut Ebrahimi Nadereh Polymer Engineering Department, Chemical Engineering Faculty, Tarbiat Modares University, P.O. Box 14115-114, Tehran, Iran aut Khoshbakhti Ehsan Polymer Engineering Department, Chemical Engineering Faculty, Tarbiat Modares University, P.O. Box 14115-114, Tehran, Iran aut Rheologica Acta Springer Berlin Heidelberg 54/2(2015-02-01), 159-168 0035-4511 54:2<159 2015 54 397 https://doi.org/10.1007/s00397-014-0822-y text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00397-014-0822-y text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Khabazian Esfahani Masood Polymer Engineering Department, Chemical Engineering Faculty, Tarbiat Modares University, P.O. Box 14115-114, Tehran, Iran aut NATIONALLICENCE 700 1- Ebrahimi Nadereh Polymer Engineering Department, Chemical Engineering Faculty, Tarbiat Modares University, P.O. Box 14115-114, Tehran, Iran aut NATIONALLICENCE 700 1- Khoshbakhti Ehsan Polymer Engineering Department, Chemical Engineering Faculty, Tarbiat Modares University, P.O. Box 14115-114, Tehran, Iran aut NATIONALLICENCE 773 0- Rheologica Acta Springer Berlin Heidelberg 54/2(2015-02-01), 159-168 0035-4511 54:2<159 2015 54 397