How is the molecular weight of highly polymerized molecules calculated?
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For high-molecular substances formed by the polymerization of oligomers, how is the molecular weight calculated, and how are mass balances performed? Such as amino resin retanning agents, the degree of polymerization of the molecules is unknown
The determination of polymer molecular weight is a specialized technique and method, and generally an appropriate approach must be selected based on the physicochemical properties of the polymer. Generally, the molecular weight distribution is characterized by dissolving the polymer in a specific solvent and observing changes in its physical or chemical properties, thereby determining the molecular weight. Molecular weight includes weight-average molecular weight and viscosity-average molecular weight, and the methods for determining these two types of molecular weight are also different. Common methods include gel chromatography, viscosity method, freezing point depression method, etc. For this type of testing, the user must choose it themselves or find a professional testing agency to do so.
This method is a standard approach that works well in large companies, but it presents problems in small businesses – they can’t afford it
So how should one calculate a rough estimate of the molecular weight? ?
Since the degree of polymerization is unknown, one can only rely on empirical values! !
Are there any organized and accessible data for this? I asked the client, and they said that the yield and ratio are calculated based on the total mass determined by considerations such as viscosity and content; molecular weight is generally not used. What kind of algorithm is this?