Development of automatic cross fractionation: Combination of crystallizability fractionation and molecular weight fractionation

Abstract

SynopsisAn automatic cross-fractionation system is presented by combining a newly developed crystallizability fractionation device based on the principle of isothermal dissolution with a commercially available GPC. The detail design, procedure, and operation variables are described. The fractions eluted from the device are characterized by use of an infrared spectrometer and a differential scanning calorimeter for clearing the mechanism of it. As the result of the study, it is found that the system is very useful for characterizing semicrystalline polymers.

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

“…Numerical interpolation smoothing spline algorithms are used in this step, in an approach similar to that described by Nakano and Goto. [12] The whole sample MWD is also recovered as the weighted sum of the MWD of individual fractions according to their weight fractions. The reconstruction of the TREF profile of the whole sample is a more complex process.…”

“…A description of this method and its application was given by Wild, starting with a preparative fractionation by TREF followed by off-line GPC analysis of the fractions. [11] The first attempt to automate an analytical system for cross-fractionation of polyolefins was presented by Nakano and Goto, [12] who combined a crystallizability fractionation device with a commercial GPC instrument. Recently, an in-house cross-fractionation system has also been described, [13] having increased throughput by using multiple TREF ovens.…”

Determination of the compositional heterogeneity of polydisperse polymer samples by the coupling of size-exclusion chromatography and thermal field-flow fractionation

“…Finally, also the cross-fractionation of polyethylene and polypropylene polymers and copolymers by means of temperature rising elution fractionation (TREF) and SEC has been employed in order to study the relationship between branching, tacticity, crystallizability or composition and molecular mass [22][23][24][25][26].…”

Copolymerization of styrene and ethylene with mononuclear and dinuclear half-titanocenes

“…The fractionation of Cyclopentadienyltitanium trichloride ( CpTiCl 3 ; polymers was recorded on cross fractionation Strem Chemical, Newburyport, MA), pentamethchromatography (CFC T-150A; Mitsubishi Petroylcyclopentadienyltitanium trichloride (Me 5 Cpchemical Co., Tokyo, Japan) in o-dichlorobenTiCl 3 , Strem Chemical), and modified methylaluzene. 15 Approximately 4 mg of polymer (0.4 wt % minoxane (MMAO-4, 7.6 wt % Al; Akzo Nobel, in o-dichlorobenzene) was loaded onto a column Deer Park, TX) were used as received. Styrene of inert packing by slow cooling, followed by step-(Junsei Chem.…”

“…The catalyst could be fractionated by on-line temperature-rising elution fractionation (TREF) to check shape of the diagram in Figure 5(A) was unimodal whereas diagrams in Figure 5(B) and (C) were the uniformity of the copolymer. 15 Therefore, the raw polymer which was obtained by copolymerizavery uniform.…”