Commercially available polyethylene glycol is a mixture of polymers obtained by polymerising monomers such as ethylene oxide, which are separated into
mixtures by approximate molecular weights. The separation of structures with similar molecular weights becomes impossible as the molecular weight increases.
For this reason, polymeric PEG with a molecular weight above 1,000 has a molecular weight distribution with a molecular weight variation of ±10-30% ( PDI = 1.02-2).
The average molecular weight is generally used as the trade name, e.g. PEG-1.4 (average molecular weight 1,400), PEG-2K (average molecular weight 2,000).
Our products are synthesised in a completely different way and have a single structure.
PDI: A number greater than 1.0; the closer to 1.0 (more zeros below the decimal point), the sharper the molecular weight distribution.
Even for small molecules with a repeat unit of 10 (molecular weight 500) or less, as shown in the data below, contained impurities with different repeat numbers and close polarities are not easy to isolate and purify.Dicarboxylic acid derived from commercial PEG.
Diamino derived from commercial PEG.