highMW

HighMW is an abbreviation commonly used to denote high molecular weight, referring to macromolecules with large molecular weights. In chemistry, polymer science, materials science, and biochemistry, highMW species are contrasted with low molecular weight compounds. The exact threshold for what counts as "high" varies by context, but many polymers and biomolecules with molecular weights in the tens of kilodaltons or higher are described as highMW.

Molecular weight is typically reported as weight-average Mw or number-average Mn, measured in Daltons (Da) or kilograms per mole (kDa). HighMW materials often display properties that differ markedly from low-molecular-weight analogs, including higher solution viscosity, greater chain entanglement, slower diffusion, and different melt rheology. The molecular weight distribution, expressed as polydispersity index (PDI), also influences performance.

Methods to determine highMW include gel permeation chromatography (GPC or SEC) with detectors such as refractive index or light scattering, sometimes coupled to multi-angle light scattering for absolute Mw. Mass spectrometry is less common for very high MW materials but increasingly used for certain biomolecules; analytical ultracentrifugation and osmometry are other tools in some cases.

Applications of highMW materials span polymer plastics, coatings, hydrogels, and drug delivery systems. In biomedicine, highMW polymers and conjugates can serve as carriers with extended circulation times. Challenges include processing difficulties due to high viscosity, solubility limits, and controlling polydispersity during synthesis.