Styrene, calibration curve

Figure 9.17 Plot of log [i ]M versus retention volume for various polymers, showing how different systems are represented by a single calibration curve when data are represented in this manner. The polymers used include linear and branched polystyrene, poly(methyl methacrylate), poly(vinyl chloride), poly(phenyl siloxane), polybutadiene, and branched, block, and graft copolymers of styrene and methyl methacrylate. [From Z. Grubisec, P. Rempp, and H. Benoit, Polym. Lett. 5 753 (1967), used with permission of Wiley.]...

Figure 3, HDC universal calibration curve (eluant ionic strength L29rriM. AM A monodisperse lattices (O) polystyrene polyvinyl chloride ( ) poly (styrene-...

Figure 4.24 Calibration curves for LiChrospher colunn. Calibration standards poly(styrene) and mobile phase tetrahydrofuran.

Determination of Pore Size Distributions. The shape and range of a GPC calibration curve are, in part, a reflection of the pore size distribution (PSD) of the column packing material. A consideration of the nature of PSDs for the ULTRASTYRAGEL columns to be used in this work is therefore appropriate. The classical techniques for the measurement of PSDs are mercury porisimetry and capillary condensation. The equipment required to perform these measurements is expensive to own and maintain and the experiments are tedious. In addition, it is not clear that these methods can be effectively applied to swellable gels such as the styrene-divinylbenzene copolymer used in ULTRASTYRAGEL columns. Both of the classical techniques are applied to dry solids, but a significant portion of the pore structure of the gel is collapsed in this state. For this reason, it would be desirable to find a way to determine the PSD from measurements taken on gels in the swollen state in which they are normally used, e.g. a conventional packed GPC column. 

How would you prepare a calibration curve if you were operating in a solvent in which poly(styrene) is not soluble ... 

Apparent values calculated on the basis of the extrapolated polystyrene calibration curve for 106A pore-size 20/i particle poly(styrene-divinyl-benzene) column. 

The GPC analysis of block copolymers is handicapped by the difficulty in obtaining a calibration curve. A method has recently been suggested to circumvent this difficulty by using the calibration curves of homopolymers. This method has been extended so that the calibration curves of block copolymers of various compositions can be constructed from the calibration curve of one-component homopolymers and Mark-Houwink parameters. The intrinsic viscosity data on styrene-butadiene and styrene-methyl methacrylate block polymers were used for verification. The average molecular weight determined by this method is in excellent agreement with osmometry data while the molecular weight distribution is considerably narrower than what is implied by the polydispersity index calculated from the GPC curve in the customary manner. 

Calibration curve of Cu(0) dissolution charge as a function of (x) Cu(l) or (o) Cu(ll) concentration in styrene solution containing 0.11 moll-1 THAP at 298.0K and v=50mVs 1. (Reprinted from Microchemical Journal, Vol 77, De Wael et al, Electrochemical detection. .., pp 85-92 (2004), with permission from Elsevier.)... 

There is a limited number of polymers for which narrow MWD standards are commercially available polystyrene, poly(methyl methacrylate), poly(a-methyl styrene), polyisoprene, polybutadiene, polyethylene, poly(dimethyl siloxane), polyethyleneoxide, pullulan, dextran, polystyrene sulfonate sodium salt, and globular proteins. In some cases, the standards available cover a limited molecular weight range, so it may be impossible to construct the calibration curve over the complete column pore volume. 

Fig. 1 Poly(styrene) (PSt) and poly(ethylene glycol) (PEG) calibration curves obtained on PL Gel column set (Mixed C,...

Figure 11. Copolymer composition (Plv), average styrene sequence length (Ns) and number average molecular weight as function of the retention volume. Molar feed composition is 0.90. PS is the polystyrene calibration curve. Key , Mn A>...

The UV absorption in the 260 nm region is frequently used to evaluate styrene content in styrene-based polymers (2, 2, 3, 4, 5, 6, 7). Calibration curves for polystyrene solutions are usually based on the assumptions that the UV absorption of the copolymer depends only on the total concentration of phenyl rings, and the same linear relationship between optical density and styrene concentration that is valid for polystyrene holds also for its copolymers. These assumptions are quite often incorrect and have caused sizable errors in the analysis of several statistical copolymers. For example, anomalous patterns of UV spectra are given by random copolymers of styrene and acrylonitrile (8), styrene and butadiene (8), styrene and maleic anhydride (8), and styrene and methyl methacrylate (9, 10, 11). Indeed, the co-monomer unit can exert a marked influence on the position of the band maxima and/or the extinction... 

Figure 9-19. A universal gel-permeation chromatography calibration curve obtained from measurements on linear poly(styrene) (O), comb-branched poly(styrene) (O ), star-branched poly(styrene) ( ), poly(methyl methacrylate) ( ), poly(vinyl chloride) (a) c -l,4-poly-(butadiene) (A), poly(styrene)-poly(methyl methacrylate) block copolymer (Qj ), random copolymer from styrene and methyl methacrylate O), and ladder polymers of poly(phenyl siloxanes) ( ) (according to Z. Grubisic, P. Rempp, and H. Benoit).

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