The interrelationships between microstructure and melting, crystallization and thermal degradation behaviors of fractionated ethylene/1-butene copolymer

Kebritchi, Abbas; Nekoomanesh, Mehdi; Mohammadi, Fereidoon; Khonakdar, Hossein Ali

doi:10.1007/s13726-015-0318-3

Cited by 9 publications

(8 citation statements)

References 54 publications

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“…This polyethylene with

{\overset{M}{true}}_{normalw} = 1.55 \times 10^{5} g/mol

{\overset{M}{true}}_{normaln} = 2.4 \times 10^{4} g/mol

, and a polydispersity of 6.5 has many short‐chain branches. The number of these branches is about 5 per 1,000 carbon . Linear low‐density polyethylene grafted by maleic anhydride (PE‐g‐MA, Orevac ® 18302N) with grafting level of 0.2–2 wt% and MFI of 1.2 g/10 min (190°C, 2.16 kg) was provided by Arkema (Colombes, France) and applied as compatibilizer at content of 6 wt%.…”

Section: Experimental Partmentioning

confidence: 99%

Compatibilized low‐density polyethylene/linear low‐density polyethylene/nanoclay nanocomposites: II. Opposing effects of nanofiller on quiescent and shear‐induced crystallization

2016

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Isothermal and non-isothermal crystallization processes of polyolefin nanocomposites based on low-density polyethylene/linear low-density polyethylene/nanoclay have been investigated, and the effects of nanoclay loading and dispersion state have been studied. Moreover, the isothermal crystallization of polyethylene chains has been evaluated in the quiescent and shear-induced conditions. In quiescent crystallization, adding 1 wt% nanofiller improves the crystallization rate, whereas an increment in the organoclay loading retards the crystallization process. However, an opposing effect of nanoparticles is observed in the shear-induced crystallization. The findings show that the incorporation of 5 wt% nanoclay in good dispersion state considerably accelerates the shear-induced crystallization process. This influence is found even for very weak shear flow fields. The synergistic effects of nanoclay addition and shear field presence on the crystallization process are of major significance particularly for polyolefin products, which are commonly manufactured by using melt processing methods. K E Y W O R D Sblend, crystallization, nanocomposite, polyethylene, shear

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“…This polyethylene with

{\overset{M}{true}}_{normalw} = 1.55 \times 10^{5} g/mol

{\overset{M}{true}}_{normaln} = 2.4 \times 10^{4} g/mol

Section: Experimental Partmentioning

confidence: 99%

Compatibilized low‐density polyethylene/linear low‐density polyethylene/nanoclay nanocomposites: II. Opposing effects of nanofiller on quiescent and shear‐induced crystallization

2016

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“…DSC melting temperature of the fractions increases with increasing TREF elution temperature (Figure 3). The correlation between DSC melting temperature and pTREF elution temperature of the fractions can be used to check the fractionation quality 16,34,35 . Hence, the almost straight‐line correlation indicates that fractionation occurred mainly according to crystallinity in both glass column and PREP mc 2 .…”

Section: Resultsmentioning

confidence: 99%

Selective experimental parameters for preparative TREF of propylene‐ethylene random copolymers: Limiting undercooling of PP

Chitta

Steenbakkers

Tacx

et al. 2021

J of Applied Polymer Sci

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Temperature rising elution fractionation (TREF) is a highly valuable and widely used tool for chemical composition separation of semicrystalline polyolefins. However, TREF operational conditions should be carefully selected due to their high impact on separation quality. This is especially true for polypropylene (PP)‐based polymers due to their slow crystallizing nature and defect distribution, which can further complicate the fractionation. In order to more fully understand this behavior, a systematic investigation was designed to determine the influence of support and cooling rate on preparative TREF of PP random copolymers. Possible measures to limit undercooling of PP and thus preventing so called co‐elution of different microstructures in TREF were demonstrated using glass beads as support during fractionation and cooling rate of 0.02°C/min. Support presence during fractionation acted as a nucleating agent to limit the elution of long isotactic chains in the low temperature fractions. Slow cooling rate along with support presence further improved the separation quality by giving the polymer chains enough time to overcome the undercooling.

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“…The data of DSC analysis of samples were summarized in Table III. As it is observed in Table III, EX3 has the lowest melt temperature and crystallinity. Kebritchi et al 37 in their investigation on the role of co-monomer content in thermal behavior of polyethylene reported that by increasing short chain branching content melting temperature decreases. Anantawaraskul et al 38 pointed out that ethylene a-olefin copolymer with more content of side chain branches shows less tendency to fold in lamellar space.…”

Section: Dsc Resultsmentioning

confidence: 99%

Effect of Molecular Structure Parameters on Crystallinity and Environmental Stress Cracking Resistance of High‐Density Polyethylene/TiO₂ Nanocomposites

et al. 2016

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ABSTRACT:The correlation between molecular microstructure with crystallization behavior and environmental stress cracking resistance (ESCR) for three commercial grades of high-density polyethylene and their nanocomposites has been investigated. Molecular architecture was characterized using high-temperature gel permeation chromatography (GPC) test. Qualitative comparison of crystallinity and side chain branches of neat high-density polyethylenes (HDPEs) has been performed using FTIR test and results were in good accordance with GPC results. Investigation of crystallinity and effect of side chain branches on the crystallite's dimensions has been carried out by DSC and XRD tests. Moreover, it was found that addition of nano-TiO 2 to HDPE causes an increase in crystal content and a decrease in crystal size, simultaneously. It was concluded from ESCR characterization that molecular weight and side chain branches are the most important structural parameters affecting ESCR properties of HDPE. The significance of side chain branches is higher compared to molecular weight.

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The interrelationships between microstructure and melting, crystallization and thermal degradation behaviors of fractionated ethylene/1-butene copolymer

Cited by 9 publications

References 54 publications

Compatibilized low‐density polyethylene/linear low‐density polyethylene/nanoclay nanocomposites: II. Opposing effects of nanofiller on quiescent and shear‐induced crystallization

Compatibilized low‐density polyethylene/linear low‐density polyethylene/nanoclay nanocomposites: II. Opposing effects of nanofiller on quiescent and shear‐induced crystallization

Selective experimental parameters for preparative TREF of propylene‐ethylene random copolymers: Limiting undercooling of PP

Effect of Molecular Structure Parameters on Crystallinity and Environmental Stress Cracking Resistance of High‐Density Polyethylene/TiO₂ Nanocomposites

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The interrelationships between microstructure and melting, crystallization and thermal degradation behaviors of fractionated ethylene/1-butene copolymer

Cited by 9 publications

References 54 publications

Compatibilized low‐density polyethylene/linear low‐density polyethylene/nanoclay nanocomposites: II. Opposing effects of nanofiller on quiescent and shear‐induced crystallization

Compatibilized low‐density polyethylene/linear low‐density polyethylene/nanoclay nanocomposites: II. Opposing effects of nanofiller on quiescent and shear‐induced crystallization

Selective experimental parameters for preparative TREF of propylene‐ethylene random copolymers: Limiting undercooling of PP

Effect of Molecular Structure Parameters on Crystallinity and Environmental Stress Cracking Resistance of High‐Density Polyethylene/TiO2 Nanocomposites

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Effect of Molecular Structure Parameters on Crystallinity and Environmental Stress Cracking Resistance of High‐Density Polyethylene/TiO₂ Nanocomposites