Polyethylene glycol is a polymer with broad application range, from detergents to pharmaceuticals and electronics. In most cases the polymer is polydisperse, which means that the material contains a distribution of very similar but not identical oligomer components. This is usually not a problem in terms of properties, but creates difficulties in their use. Commercial PEGs of same molecular weight often have batch variations, and differ from supplier to supplier. Further problems arise in characterization and purity control. The use of heterogeneous materials in challenging applications therefore becomes unsuitable.
By providing highly fractionated oligomers, we eliminate most of these complicating factors, and the favourable attributes are better presented. This already shows for the chemical modification of the PEG chain, where intermediate and product quality can be ensured by thorough characterization and purification schemes.
One example is shown to the left. A PEG mono-methacrylate was prepared as a custom synthesis product from octaethylene glycol, with specifications <2% of bis-methacrylate. HPLC analysis confirms the satisfactory result. A comparable product made from a polydisperse PEG may be obtained from other commercial source. The analysis under the same conditions indicate a peak component with n=6 along with a range of similarly modified oligomers. Further noticeable are the accompanying distribution of un-modified PEG 300, and a presumable distribution of by-products overlapping the late part of product peaks. Late eluting materials are of unknown origin, but may partly be due to inhibitors and other additives.
You may go through our compiled list of literature references , where the high purity PEG and derivatives has been used for various applications. We appreciate if you let us know if there are more to append to this growing list.