Chemical purity and oligomer uniformity are paramount to Polypure’s customers. You may wonder what the difference is between chemical and oligomer purity. A polymeric chemical (i.e. PEG) is composed of various oligomers produced during the polymerization process. While bulk PEG may have minimal non-native substances, the distribution of oligomers compromises its applicability. Polypure defines oligomer purity by the unity of oligomer content.  Alternatively, it can be described by the monodispersity of the PEG.

Polypure was founded to provide the highest purity PEG based products. This starts by purifying polydisperse bulk PEG of high chemical purity into uniform PEG oligomers. The chromatograms below exemplify our typical uniform PEG-8 oligomer with side chain oligomers significantly below our specification limits (less than 5%) as compared with PEG 400. The uniform oligomers can then be functionalized into high value PEG derivatives. If necessary, they are purified by standard chemical means or reprocessed using our proprietary technology.

The use of monodisperse PEG and SDC purification technology results in exceptionally high performance products for our customers.

Sample Displacement Chromatography

Polypure’s unique technology is based on the principles of sample displacement chromatography (SDC).  The process leverages the competition effects between sample components—not the elution behaviors used in liquid chromatography. The SDC process retains high sample resolution without the high pressures and scaling complexities of HPLC. 

The column systems are optimized for species binding to sort samples by length. We can then effectively locate specific oligomers for extraction with resolutions approaching unity. Polypure products generally have a 

specification limit for non-target oligomers of less than 5 percent. However, our internal control limit is far tighter.

Our SDC processes are cost-effective and optimized to produce market tested specialty chemicals. Polypure’s systems operate efficiently with highly concentrated solutions and do not require exotic solvents or reagents. As we continue to grow, we have increased capacity and scaled production units to meet market demand.

SDC Key Mechanisms

  • Stationary phase Interactions: Hydrophobic (RPC), Charge (IEX), Affinity

  • Competition effect: Selectivity generated only by sample Components

  • On-Off mechanism: Binding conditions during separation, Extraction for recovery


Production output at Polypure has increased to several hundred kilograms annually. The last couple of years we have significantly increased efficiency and added capacity as demand grows for high performance PEG materials. Scale-up has been in collaboration with our customers to reliably meet their needs for unique high value PEG derivatives. Having successfully boosted production volume and expanded product variety, we have developed the know-how and capacity to serve more clients with unique offerings.

Cases for Monodisperse PEG

Polypure AS

Gaustadalleen 21
NO-0349 Oslo, Norway
+47 21 08 07 40