Development of an Automated Cross‐Fractionation Apparatus (TREF‐GPC) for a Full Characterization of the Bivariate Distribution of Polyolefins

Ortín, A.; and, Benjamin Monrabal; Sancho-Tello, Juan

doi:10.1002/9783527623679.ch2

Cited by 3 publications

(3 citation statements)

References 6 publications

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“…Several groups have built similar setups for offline TREF × SEC [37][38][39][40][41][42]. Automation in TREF × SEC was first realized by Nakano et al [43], and in the meantime a fully automated instrument has been commercialized by Ortín et al [44]. Yet, TREF suffers from limitations, which render it unsuitable for BiHDPE.…”

Section: Introductionmentioning

confidence: 97%

Separation of bimodal high density polyethylene using multidimensional high temperature liquid chromatography

Prabhu

Brüll

Macko

et al. 2015

Journal of Chromatography A

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Section: Introductionmentioning

confidence: 97%

Separation of bimodal high density polyethylene using multidimensional high temperature liquid chromatography

Prabhu

Brüll

Macko

et al. 2015

Journal of Chromatography A

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“…Pasch et al studied the correlation between the polymer chain microstructure and the thermal behaviour of various components in a complex impact polypropylene copolymer through the combination of preparative TREF, FTIR, DSC and high temperature two-dimensional liquid chromatography [24]. Monrabal characterized polypropylene and polyethylene blends by combinations TREF and crystallization analysis fractionation [25]. Yau applied GPC coupled with triple detectors and TREF to obtain valuable information on the polyolefin microstructures [26].…”

Section: Introductionmentioning

confidence: 99%

Molecular chain heterogeneity of a branched polyethylene resin using cross-fractionation techniques

Xue

2015

J Polym Res

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The typical standard long chain branching (LCB) polyethylene (PE) SRM1476 is issued by the American National Bureau of Standards, which is widely used as a standard reference material in chromatographic experiments. Although some works have been reported in literatures, they are not consistent, such as the data about its molecular weight and molecular weight distribution. Therefore, it is necessary to further investigate the microstructure features of SRM1476 in order to better serve as a reference object in comparison with other unknown resins. In this study, the molecular chain heterogeneity of SRM1476 is investigated extensively and compared with the linear PE SRM1475. Based on the characterization of the original sample, SRM1476 actually has both LCB and short chain branching (SCB) structures, as well as the SCB content is more than LCB content in 13 C-NMR results. After successive self-nucleation and annealing (SSA) thermal fractionation, SRM1476 shows a broad-range endotherm with multiple melting peaks (more than eight peaks), which proves the molecular chain heterogeneity in SRM1476. SRM1476 is fractionated into nine fractions by preparative temperature rising elution fractionation (TREF). At the high elution temperature region, the amounts of fractions are more than 90 %, and their molecular weights are higher. At the low elution temperature region below 50°C, molecular weights of fractions are lower and their amounts are less than 5 %. Differential scanning calorimetry (DSC) melting curves of TREF fractions with higher elution temperatures shift toward higher temperature with sharper melting peaks. In the results of TREF-SSA cross-fractionation, each fraction shows a broadrange endotherm with multiple melting peaks that shift toward the high elution temperature region with the elution temperature. The arithmetic mean methylene sequence lengths of TREF fractions gradually increase from 33 to 105 as elution temperature increases. Results from TREF-DSC and TREF-SSA cross-fractionations indicate that SRM1476 and its TREF fractions have both intramolecular and intermolecular heterogeneity.

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“…The multidimensional chromatography applied in this work is cross fractionation chromatography (CFC). This method is based on the in situ combination of temperature-rising elution fractionation (TREF) and size exclusive chromatography (SEC) 26,27 in the TREFxSEC mode. The detailed working principle is sketched in the Supporting Information and further described in ref 22.…”

mentioning

confidence: 99%

Lattice-Cluster-Theory-Informed Cross-Fractionation Chromatography Revealing Degree of Crystallinity of Single Macromolecular Species

Fan,

Zimmermann,

Ciacchi

et al. 2024

ACS Macro Lett.

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The relationship between macromolecular architecture and crystallization properties is a relevant research topic in polymer science and technology. The average degree of crystallinity of disperse polymers is a wellstudied quantity and is accessible by various experimental methods. However, how the different macromolecular species contribute to the degree of crystallinity and, in particular, the relationship between a certain macromolecular architecture and the degree of crystallinity are not accessible today, neither experimentally nor theoretically. Therefore, in this work, a lattice cluster theory (LCT)-informed cross-fractionation chromatography (CFC) approach is developed to access the degree of crystallinity of single and nonlinear macromolecular species crystallizing from solution. The method entangles high-throughput experimental data from CFC with the LCT for semicrystalline polymers to predict the degree of crystallinity of polymer species with different molecular weights and branching. The approach is applied to a linear low-density polyethylene (ethylene/1-octene copolymer) and a high-density polyethylene, which have specific and different bivariate distributions. The degree of crystallinity of individual macromolecular species of these polymer samples is calculated, and the predicted average degree of crystallinity is compared with experimental measurements, thus successfully validating the approach. Furthermore, the average segment length between branches is introduced as a characteristic molecular feature of branched polyethylene, and its relationship with the degree of crystallinity of certain species is established.

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Development of an Automated Cross‐Fractionation Apparatus (TREF‐GPC) for a Full Characterization of the Bivariate Distribution of Polyolefins

Cited by 3 publications

References 6 publications

Separation of bimodal high density polyethylene using multidimensional high temperature liquid chromatography

Separation of bimodal high density polyethylene using multidimensional high temperature liquid chromatography

Molecular chain heterogeneity of a branched polyethylene resin using cross-fractionation techniques

Lattice-Cluster-Theory-Informed Cross-Fractionation Chromatography Revealing Degree of Crystallinity of Single Macromolecular Species

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