Structure-Property Relationships in Low-Density Polyethylene
Titel:
Structure-Property Relationships in Low-Density Polyethylene
Auteur:
Ram, Arie Miltz, Joseph
Verschenen in:
International journal of polymeric materials
Paginering:
Jaargang 2 (1972) nr. 1 pagina's 39-47
Jaar:
1972-10-01
Inhoud:
Modern techniques were adopted and utilized for molecular-weight characterization of commercial low-density (branched) polyethylenes. The index of long-chain branching was uniquely related to that of molecular-weight dispersion, Dn. Two groups of low-density polyethylenes were visualized, differing in width of MW distribution and in the branching index. An attempt was made to relate the flow properties, melt-flow index (MFI) and intrinsic viscosity [n], as well as some physical properties-density, tensile strength, ultimate elongation and resistance toenvironmental stress cracking-toatypical molecular parameter. In all correlations, the two groups are represented by two distinctly different curves. By combining the parameter g for long-chain branching with the weight average molecular weight, M¯γ, the flow parameters are unified into single curves. The mechanical properties studied were found to improve increasing M¯γ and with narrowing of the molecular-weight distribution.
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