Polymethylmeth-acrylate (PMMA) calibration standard
Narrow MW polymer
The calibration kit for organic SEC
Product information
The Shodex STANDARD M-75 is Polymethylmethacrylate for SEC, and it is suitable for SEC using hexafluoroisopropanol (HFIP) and dimethylformamide (DMF) solvent. Other usable solvents are tetrahydrofuran (THF), toluene, methyl ethyl ketone, ethyl acetate, DMF, and DMAc.
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For organic solvent SEC (GPC)
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Narrow molecular weight distribution range
Chromatographic determinations of the molecular weight (MW) properties of polymers, either in organic or aqueous phase, rely on calibration with Standards of highly characterized MWs for accurate results. Expressed simply, Size Exclusion (or Gel Permeation) Chromatography enables polymer molecules of different sizes in solution to be separated from one another, such that the large molecules elute first and small molecules elute last.
Since the molecular size in solution (hydrodynamic volume) is related to MW, a picture of the entire MW Distribution (MWD) may be obtained quickly and simply. This is in great contrast to the “absolute” techniques of MW determination which frequently could take half a day per sample to define a single average MW.
Polymer Standards are thus an integral part of any quantitative Size Exclusion Chromatography. These Standards need to be highly characterized by as many absolute and chromatographic techniques as possible to define the MW averages and MWD. The closer the value of the MWD is to unity, the sharper will be the polymer peak and the better the material will be for a Calibration Standard.
Note: Molecular weights (Mp, Mw/Mn) of a standard kit or each single type may vary depending on production lots. Always refer to the inspection certificate.
Product overview
Product code | Product name | Compound | Type | Content | Molecular weights (Mp) Range* |
|---|---|---|---|---|---|
F8604075 | STANDARD M-75 | Polymethylmethacrylate | Kit | 0.5 g x 7 kinds | approx. 3,000 – 1,000,000 |
Product instruction
Preparation of solutions
It is recommended as a general principle that the polymer concentration in solution and the injection volume both be kept as low as possible concurrent with the sensitivity of the system to reduce as much as possible deleterious effects such as column broadening and viscous trapping. This becomes even more critical when very high molecular weights are involved. Solutions should be made up at room temperature only.
Handling of MWs above 1,000,000 should avoid degradation of polymer when making up a solution. It is recommended that gentle agitation by hand is used at intervals throughout a 24 hr period, by which time complete dissolution will normally occur.
Storage
Polymethylmethacrylate Standards are stable materials themselves, but these are degraded by air, sunlight and heat. So that Polymethylmethacrylate Standards should be stored at room temperature of 20 to 25°C, and in the dark place. They should not be stores in direct sunlight or in wide temperature change.