Polymer Molecular Weight Determination

Polymer molecular weight determination will play an important role in the development of new polymer materials, ongoing processing / production over the polymer’s lifecycle and its performance in the finished product.  
A polymer's properties and performance are influenced by its molecular weight distribution. A high molecular weight, for example, can influence both a polymer’s brittleness as well as tensile strength. A low molecular weight can have an influence on a polymer’s melt processing abilities. 

Our polymer testing laboratories regularly perform molecular weight (Mw) determination for polymer materials helping our clients to progress new polymer development and material selection, address degradation or materials failure issues and monitor quality across production.

We apply a range of molecular weight analysis techniques to study the integrity of the material and establish any deviations which may lead to problems such as breakage, crazing and long-term degradation. Our laboratories work with organizations of all sizes from the largest OEMs to the smaller niche polymer material developers. We provide the number-average molecular weight (Mn), mass-average molecular weight (Mw), z-average molecular weight (Mz) and Polydispersity (Mw/Mn) of a molecular weight distribution for a broad range of both polymers. 

Gel Permeation Chromatography (GPC) is widely used in various fields for molecular weight determination. Here are the key applications of GPC:

1.    Polymer Characterization: GPC is extensively used to determine the molecular weight distribution of both synthetic and natural polymers. It helps assess the polymer’s properties, such as chain length, uniformity, and overall structure, which influences both their physical and mechanical properties.
2.    Quality Control in Manufacturing: Molecular weight analysis using GPC is used in industries such as plastics, coatings, and adhesives to monitor the quality of polymer products. By checking the molecular weight distribution of a polymer, manufacturers ensure that products meet the required specifications for their performance criteria.
3.    Polymer Blends and Composites: Polymer molecular weight determination is used in the study of polymer blends and composites; GPC helps to analyze the molecular weight of individual components. This is essential for understanding the behavior and compatibility of different polymers when blended.
4.    Biopolymers and Proteins: GPC is applied in biochemistry to determine the molecular weight of biopolymers, such as proteins, nucleic acids, and polysaccharides. It can be used for characterizing the size of proteins or studying protein folding and aggregation.
5.    Characterization of Polymers in Solution: GPC is used to analyze the behavior of polymers in different solvents, by comparing their mw vs mn (PD) helps us to understand their various properties, such as viscosity, solubility, and polymer aggregation.

GPC’s versatility in determining molecular weight and molecular weight distributions makes it indispensable in research, industry, and quality control across various applications. Intertek's polymer scientists perform MW determination for a wide range of polymer materials including acrylics, acrylates, polystyrene, polycarbonates, polysiloxanes. Additionally we also analyse rubbers, resins, silicone fluids, prepolymers and polyols. Our scientists determine the MW of polymers, soluble in organic solvents (eg. THF, Toluene, Chloroform, DMF, and others) and also soluble in water.

GPC Expertise:

• Gel Permeation Chromatography
• High Temperature Gel Permeation Chromatography (HT-GPC)
• GPC-NMR 
• Aqueous GPC
• Conventional (calibration based) GPC-DRI (Differential Refractive Index detection) with polystyrene-standard (PS)-calibration or polymethylmethacrylate standards (PMMA)-calibration.
• Detection: GPC-UV / RI / SFD / Viscosimetry / ELSD / Light Scattering Detection.
• Multi Angle Laser Light Scattering (MALLS)

The molecular weight properties of a polymer may vary over the life cycle of a material as the polymer progresses through stages such as raw material, molding, sterilization, and storage. Our testing, insight and advice can assist you in your decision-making process and help to ensure the integrity of the product.

Our expert polymer molecular weight measurement services, delivered from our laboratories in Europe and the USA, can help you to understand the composition and properties of your polymer materials and address processing and material failure issues throughout the material and product’s lifetime.