Branched poly(ethylene terephthalate) correlations between viscosimetric properties and polymerization parameters
1976; Elsevier BV; Volume: 17; Issue: 7 Linguagem: Inglês
10.1016/0032-3861(76)90275-5
ISSN1873-2291
AutoresP. Manaresi, Paolo Parrini, Gian Luigi Semeghini, E DEFORNASARI,
Tópico(s)Microplastics and Plastic Pollution
ResumoSamples of poly(ethylene terephthalate) (PET) modified with small amounts of trimesic acid groups and hence containing long chain branching have been prepared. From the content of trifunctional modifier and from the experimental value of the extent of reaction, the weight-average molecular weight M̄w and branching density B̄w have been calculated, assuming that all the end-groups are equally reactive and intramolecular reactions are absent. The values of M̄w and B̄w have been correlated with the experimental values of intrinsic viscosity [η] and the Newtonian melt viscosity η0. General relations of the following type have been obtained: f1([η], Mw, Bw) = 0; f2(η0, Mw, Bw) =0; f3(η0, [η], Bw) = 0; f4(η0, [η], Mw) = 0; In particular, [η] and η0 increase on increasing M̄w and decrease on increasing B̄w, but, at equal [η] values, η0 increases with B̄w. Through the last relation, the reliability limits of which should be experimentally checked, and from measurements of [η] and η0, it is possible to calculate M̄w of a branched PET.
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