Mark–Houwink equation and GPC calibration for linear short‐chain branched polyolefines, including polypropylene and ethylene–propylene copolymers
1984; Wiley; Volume: 29; Issue: 12 Linguagem: Inglês
10.1002/app.1984.070291211
ISSN1097-4628
AutoresTh. G. Scholte, Nico Meijerink, H. M. Schoffeleers, A. M. G. Brands,
Tópico(s)Protein Structure and Dynamics
ResumoAbstract The reduction in molecular dimensions due to the presence of short side chains in otherwise linear polyolefins can very simply by calculated by assuming that the configuration of the main chain is not influenced by the side chains. This enables us to express the intrinsic viscosity–molar mass relationship as a function of the mass fraction of side chains ( S ): [η] = (1 − S ) α+1 K PE M ν α and, with use of the universal calibration principle, to convert the GPC calibration for purely linear polymers samples into the calibration for short‐chain branched polymers: M * = (1 − S ) M . Experimental data from literature on short‐chain branched poly‐ethylenes, and our own data on ethylene–propylene copolymers are used to verify the above assumption. It appears that the experimentally found relations between [η], M w and M * w ( GPC ) within the usual accuracy justify this approach.
Referência(s)