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Chain extension of recycled P A 6
Author(s) -
Tuna Basak,
Benkreira Hadj
Publication year - 2018
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.24663
Subject(s) - materials science , polymer , rheology , degradation (telecommunications) , epoxy , amide , extender , viscoelasticity , long chain , polymer science , chain (unit) , polymer chemistry , reactive extrusion , viscosity , chemical engineering , composite material , organic chemistry , chemistry , computer science , polyurethane , telecommunications , physics , astronomy , engineering
Recycling of polymers is a necessity in our intensively consuming polymer world but the nature of polymers is such that they are prone to thermal degradation when re‐extruded and this poses technical challenges to recycling. This article describes research that seeks to rebuild the structure of degraded PA6. We present data from controlled experiments with pristine pPA6 extruded to form a base recycle rPA6 to which we added two chain extenders, separately: one with anhydride multifunctionality (ANHY), highly reactive with amide groups and one with epoxy multifunctionality (EPOX), less reactive. We found from rheological data carried out in the linear viscoelastic region (so as to study structural changes) a striking difference in the ability of the chain extenders to rebuild structure: 306% increase in the complex viscosity of rPA6/ANHY compared to 25% in that of rPA6/EPOX of the base rPA6. Mechanical and thermal (DSC and TGA) tests confirmed the superior efficacy of the multifunctional anhydride chain extender. Beside the practical benefit that ensues from this research, it also provides a strategic platform to develop chain extenders for other degrading polymers on the basis of understanding the degradation chemical reaction and targeting the most reactive end group of the split chains. POLYM. ENG. SCI., 58:1037–1042, 2018. © 2017 Society of Plastics Engineers