Styrene copolymers chromatography

Mori, S., Size exclusion chromatography and nonexclusion liquid chromatography for characterization of styrene copolymers, Adv. Chem., 247, 211, 1995. 

A simple but elegant example of the broad utility of mass chromatography is shown in Figure 6. In this case, a polymer sample was thermally decomposed at 400°C, and the products were analyzed. The molecular weight, retention time, and quantitative analyses of the major products indicated that the sample was a 69% methyl methacrylate-31% styrene copolymer. 

Chromatographic System Determine as directed under Chromatography, Appendix HA, but use a liquid chromatograph equipped with a differential refractometer detector and a 30-cm x 7.8-mm (id) column packed with 25-pm diameter beads of silver bonded to sulfonated divinyl benzene-styrene copolymer (Aminex HPX-42A, Bio-Rad Laboratories, or equivalent). Maintain the column at a constant temperature of 65° 10°, and the flow rate at 0.3 to 1.0 mL/min. Use deionized water as the mobile phase. 

Size-Exclusion Chromatography and Nonexclusion Liquid Chromatography for Characterization of Styrene Copolymers... 

Mori, S. Size-exclusion and nonexclusion liquid chromatography for characterization of styrene copolymers. In Chromatographic Characterization of Polymers Hyphenated andMultidimensionalTechniques (Provder, T., Barth, H. G., and Urban, M., Eds.), ACS Advances in Chemistry Series 247 American Chemical Society Washington, DC, 1995, p. 211. 

The suspension polymerisation approach is often used in the production of polyvinyl chloride dispersions for use in plastic pipes. Polystyrene and styrenic copolymers are also produced by suspension polymerisation. The polystyrene beads are often prepared by suspension polymerisation for use as packing material in gel permeation chromatography (GPC) columns. Ion exchange resin beads are also commonly produced by suspension polymerisation. Because suspension beads are relatively large, it is easier to separate the polymer by coagulation than in the case of emulsion polymerisation. 

Zhang ZR, Saetre R. Characterization of styrene copolymers using size-exclusion chromatography with on-line FT-IR and viscometer detectors. Int J Poly Anal Char 2007 12 185-201. 

Ethylene-styrene copolymer Ethylene-vinyl acetate copolymer Ethylene-vinylchloride copolymer Fourier transform infrared spectroscopy Gas chromatography High-density polyethylene Hydroperoxide decomposition Isobutylene... 

Rgure 19.2 shows several gel permeation chromatography (GPC) curves of the styrene/B-styrene copolymers (runs A-1, A-2, A-4, A-5, and A-7 in Tablel9.1) prepared by the Cp Ti(OMe)3/MAO complex. The narrow molecular weight distribution in all samples, with M /M = 2-3, implies that the... 

Products obtained by pyrolysis of other polymers is reviewed in Table 4.5. Some specific applications of the chromatography-MS technique to various types of polymers include the following PE [34,35], poly(l-octene) [29], poly(l-decene) [29], poly(l-dodecene) [29], CPE [36], polyolefins [37, 38], acrylic acid-methacrylic acid copolymers [39, 40], polyacrylate [41], nitrile rubber [42], natural rubbers [43, 44], chlorinated natural rubber [45, 46], polychloroprene [47], PVC [48-50], polysilicones [51, 52, 53], polycarbonates [54], styrene-isoprene copolymers [55], substituted olystyrene [56], PP carbonate [57], ethylene-vinyl acetate [58], Nylon 66 [59], polyisopropenyl cyclohexane-a-methyl styrene copolymers [60], cresol-novolac epoxy resins [61], polymeric flame retardants [62], poly(4-N-alkyl styrenes) [63], polyvinyl pyrrolidone [64], polybutyl-cyanoacrylate [65], polysulfides [66], poly(diethyl-2-methacryl-oxy) ethyl phosphate [67, 68], polyetherimide [69], bisphenol-A [70], polybutadiene [71], polyacenaphthalene [72], poly(l-lactide) [73], polyesterimide [74], polyphenylene triazine [75], poly-4-N-vinyl pyridine [76], diglycidylether-bisphenol-A epoxy resins [77], polyvinylidene chloride [78] and poly-p-chloromethyl styrene [79]. 

Ozonisation followed by gel permeation chromatography (GPC) has been used by Tanaka and co-workers [78,79] to study sequencing of vulcanised styrene copolymers. Tanaka and co-workers [78, 79] carried out the ozonolysis in methylene dichloride and examined the fractions obtained following GPC by H-NMR. These workers found nonad, diad and triad styrene sequences flanked by 1,4-butadiene units and long styrene sequences ... 

Modern SEC columns are packed with material other than polystyrene gels, such as porous silica particles or highly cross-linked styrene-divinylbenzene copolymers. Because of improvements in speed and resolution, the term SEC is sometimes replaced by the term high-performance size-exclusion chromatography (HPSEC). 

Figure 12.8 Mia ocolumn size exclusion chromatogram of a styrene-aaylonitrile copolymer sample fractions ti ansfeired to the pyrolysis system are indicated 1-6. Conditions fused-silica column (50 cm X 250 p.m i.d.) packed with Zorbax PSM-1000 (7p.m 4f) eluent, THF flow rate, 2.0 p.L/min detector, Jasco Uvidec V at 220 nm injection size, 20 nL. Reprinted from Analytical Chemistry, 61, H. J. Cortes et al, Multidimensional chromatography using on-line microcolumn liquid chromatography and pyrolysis gas chromatography for polymer characterization , pp. 961 -965, copyright 1989, with peimission from the American Chemical Society.

These small columns,(usually 10 mm X 1-4.6 mm i.d.) are normally packed with 10-40 p.m sorbents such as Cig-bonded silica, Cg-bonded silica or styrene-divinylbenzene copolymer. These sorbents are not very selective and more selective sorbents, such as the immunosorbent (94), have also been used with good results. Coupling of SPE-gas chromatography is in fact the one most often used in environmental analysis because it reaches a high level of trace enrichment, eliminates water and elutes retained compounds easily with an organic solvent that can be injected into the gas chromatograph. 

The most common technique used for agrochemicals is reversed-phase SPE. Here, the bonded stationary phase is silica gel derivatized with a long-chain hydrocarbon (e.g. C4-C18) or styrene-divinylbenzene copolymer. This technique operates in the reverse of normal-phase chromatography since the mobile phase is polar in nature (e.g., water or aqueous buffers serve as one of the solvents), while the stationary phase has nonpolar properties. 

Mori, S., Separation and detection of styrene-alkyl methacrylate and ethyl methacrylate-butyl methacrylate copolymers by liquid adsorption chromatography using a dichloroethane mobile phase and a UV detector, J. Chromatogr., 541, 375, 1991. 

Bravo, 1984). Hybrids of these systems, where chromatography and electrophoresis are used in each spatial dimension, were reported nearly 40 years ago (Efron, 1959). Belenkii and coworkers reported on the analysis of block copolymers by TLC (Gankina et al., 1991 Litvinova et al., 1991). Two-block copolymers of styrene and f-butyl methacrylate were separated first with regard to chemical composition by TLC at critical conditions, followed by a SEC-type separation to determine the molar masses of the components. 

F.C. Y.Wang and P.B. Smith, Quantitative analysis and structure determination of styrene/ methyl methacrylate copolymers by pyrolysis gas chromatography, Anal. Chem., 68, 3033 3037(1996). 

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