|
Authors
|
Kebritchi, A. ; Nekoomansh, M. ; Mohammadi, F. ; Khonakdar, H. A.
|
|
Title
|
The interrelationships between microstructure and melting, crystallization and thermal degradation behaviors of fractionaed ethylen/1-butene copolymer
|
|
Date
|
01.04.2015
|
|
Number
|
46801
|
|
Abstract
|
The interrelationships between microstructure and melting, crystallization and thermal degradation behaviors of a commercial Ziegler–Natta (Z–N)-based ethylene/1-butene copolymer were investigated. The copolymer was fractionated based on short chain branch (SCB) content by preparative temperature-rising elution fractionation (P-TREF) method. A broad multipeak chemical composition distribution was obtained for both molecular weight distribution and short chain branch distribution. A difference of about 48 °C in melting temperature (T m) has been observed for fractions with 50 branches of different SCB contents. A logarithmic relationship was obtained between the methylene sequence length calculated based on proton-1 nuclear magnetic resonance results and the P-TREF elution temperature (ET). A relationship between the SCB content and the inverse of lamellae thickness (L c) was established. Two linear functionalities were found for T m versus ET and crystallization temperature (T c) versus the SCB content. To the best of our knowledge, as a first effort, surprisingly a linear relationship between the temperature at the maximum rate of degradation (T max) and the SCB content was acquired, which showed less sensitivity to the SCB content than T m. Also, it was found that the degradation initiation temperature (T 5%) and activation energy (E a) are increased by the decreasing SCB content. Moreover, it was demonstrated that Hosoda equation is not applicable for different ethylene/a-olefin copolymers based on different catalyst types with dissimilar fractionations and experimental conditions.
|
|
Publisher
|
Iranian Polymer Journal
|
|
Wikidata
|
|
|
Citation
|
Iranian Polymer Journal 24 (2015) 267-277
|
|
DOI
|
https://doi.org/10.1007/s13726-015-0318-3
|
|
Tags
|
|
