MIL-HDBK-17-1F Volume 1,Chapter 4 Matrix Characterization TABLE 4.4.5 Polymer molecular weights,molecular Standard Techniques Parameters Measured Size-Exclusion Chromatography Mol.wgt.averages and MWD,also provides (SEC)informa- tion relating to polymer chain branching,copolymer compo- sition,and polymer shape. Light Scattering(Rayleigh) Weight-average mol.wgt.Mw (g/mol),virial coefficient A2 (mol.cc/g),radius of gyration <R(A),polymer structure, anisotropy,polydispersity. Membrane Osmometry Number-average mol.wgt.M(g/mol),virial coefficient A2 (mol cc/g).Good for polymers with MW's in the range 5000 MW 105,lower MW species must be removed. Vapor Phase Osmometry Same as membrane osmometry except that the technique is best suited for polymers with MW<20,000 g/mol. Viscometry(dilute solution) Viscosity-average mol.wgt.Mn(g/mol)as determined by intrinsic viscosity [n](ml/g)relationship []KM,where K and a are constants. Ultracentrifugation or Sedimentation Sedimentation-diffusion average mol.wgt.Msd as defined by the relationship Md=S /D..Number-and z-average mol. wgt.,Mn and Mz.MWD determined by the relation S=kM2 where k and a are constants.Also provides information on the size and shape of polymer molecules. Special Techniques Parameters Measured Ebulliometry Number-average mol.wgt.M (g/mol)for M<20,000 g/mol. Cryoscopy Number-average mol.wgt.M(g/mol)for M<20,000 g/mol. End Group Analysis Number-average mol.wgt.M(g/mol generally for M< 10,000.Upper limit depends on the sensitivity of the ana- lytical method used. Turbidimetry Weight-average mol.wgt.M(g/mol)and MWD based upon solubility considerations and fractional precipitation of polymers in very dilute solutions 4-8MIL-HDBK-17-1F Volume 1, Chapter 4 Matrix Characterization 4-8 TABLE 4.4.5 Polymer molecular weights, molecular Standard Techniques Parameters Measured Size-Exclusion Chromatography Mol. wgt. averages and MWD, also provides (SEC) informa￾tion relating to polymer chain branching, copolymer compo￾sition, and polymer shape. Light Scattering (Rayleigh) Weight-average mol. wgt. Mw (g/mol), virial coefficient A2 (mol. cc/g2 ), radius of gyration <Rg>z(A), polymer structure, anisotropy, polydispersity. Membrane Osmometry Number-average mol. wgt. Mn (g/mol), virial coefficient A2 (mol cc/g2 ). Good for polymers with MW's in the range 5000 < MW < 106 , lower MW species must be removed. Vapor Phase Osmometry Same as membrane osmometry except that the technique is best suited for polymers with MW < 20,000 g/mol. Viscometry (dilute solution) Viscosity-average mol. wgt. Mη (g/mol) as determined by intrinsic viscosity [η] (ml/g) relationship [η] = KMv where K and a are constants. Ultracentrifugation or Sedimentation Sedimentation-diffusion average mol. wgt. Msd as defined by the relationship Msd = Sw/Dw. Number- and z-average mol. wgt., Mn and Mz. MWD determined by the relation S = kMa where k and a are constants. Also provides information on the size and shape of polymer molecules. Special Techniques Parameters Measured Ebulliometry Number-average mol. wgt. Mn (g/mol) for Mn < 20,000 g/mol. Cryoscopy Number-average mol. wgt. Mn (g/mol) for Mn < 20,000 g/mol. End Group Analysis Number-average mol. wgt. Mn (g/mol generally for Mn < 10,000. Upper limit depends on the sensitivity of the ana￾lytical method used. Turbidimetry Weight-average mol. wgt. Mw (g/mol) and MWD based upon solubility considerations and fractional precipitation of polymers in very dilute solutions