Gel permeation chromatography: Universal calibration for polypropylene

Abstract

Twelve well-characterized fractions of polypropylene and a set of polystyrene standard samples are used to establish the universal calibration in gel permeation chromatography for polypropylene in 1,2-dichlorobenzene at 135°C. The Mark-Houwink relation under those conditions and the unperturbed dimensions are determined for polypropylene. Comparisons are made with earlier work with less well characterized samples. ZUSAMMENFASSUNG:Zwolf gut charakterisierte Polypropylen-Fraktionen und ein Satz von Polystyrol-Standardpraparaten werden benutzt, um fur Polypropylen in 1,2-Dichlorbenzol bei 135 "C eine universelle Eichbeziehung fur die Gelchromatographie aufzustellen. Die Viskositats-Molekulargewichtsbeziehung unter diesen Bedingungen und die ungestorten Dimensionen werden fur Polypropylen bestimmt. Die Ergebnisse werden mit alteren Messungen an weniger gut charakterisierten Praparaten verglichen. *) Throughout this paper the term "molecular weight" replaces the more correct "relative molecular mass". 2 0 $ at 135 "C). z 5' b, In 1-chloronaphthalene at 140°C and 546nm; estimated from ref."). By vapour pressure osmometry; the rest by membrane osmometry. e, Solutions were coloured; R, estimated from [ q ] vs. M , relation. ' ) Estimated from GPC and M,. a) mn (by membrane osmometry), m, (by light scattering), and a, (determined from Eq. (2) with a=0,7) are the number, weight, and viscosity average molecular weights; dn/dc: refractive index increment; [q] : intrinsic viscosity (measured in 1,2-dichlorobenzene 3 z 7 3 d, Uncertainty in M,, estimated to be f 10%. u' 9) NBS standard linear polyethylene used as calibrant. 2 c! v,

Mark–Houwink equation and GPC calibration for linear short‐chain branched polyolefines, including polypropylene and ethylene–propylene copolymers

“…A&, values were determined direct by means of the SOFICA and the Chromatix KMXS equipment as well as by GPC, using the KMX-6 on-line. From the results of these measurements, the [q] values found, and the i%Z, values given by NPL, 29 The intrinsic viscosities in decalin or TCB of six linear polypropylene homopolymer samples and a large number of fractions of these samples were also measured, and gel permeation chromatograms (in TCB) for the same substances were prepared to determine M*, and M*,, values. We thus arrived at the following relation:…”