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Chain Extension of Oligoamide or Polyamide in an Extruder
Author(s) -
Schacker Ottmar,
Braun Dietrich,
Hellmann Götz P.
Publication year - 2001
Publication title -
macromolecular materials and engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.913
H-Index - 96
eISSN - 1439-2054
pISSN - 1438-7492
DOI - 10.1002/1439-2054(20010701)286:7<382::aid-mame382>3.0.co;2-7
Subject(s) - polyamide , materials science , monomer , polymer chemistry , grafting , polystyrene , chain (unit) , polymer , polymer science , chemical engineering , composite material , physics , astronomy , engineering
Polycondensates with too short chains can be chain‐extended with repair molecules. In this report, the molecular weight and, thereby, the melt viscosity of polyamides is enhanced in the extruder by two chemically very different types of repair molecules. Firstly, the chains were extended linearly with a bisoxaline which is a well‐known strategy. Secondly, polyamide chains were bundled by grafting onto a functionalized backbone chain, i. e., maleinated polystyrene (SMA). This less known route leads to branched rather than linear chain extension. Despite the fact that the melts of branched chains are less viscous than those of linear chains, at the same molecular weight, the viscosity of polyamides was markedly increased by grafting onto SMA. Grafting of oligoamide and polyamide chains was studied, as well as grafting of the monomer of the polyamide in combination with its polycondensation.