Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5201636 | Polymer Degradation and Stability | 2014 | 9 Pages |
Abstract
The combined effect of melt annealing and surface modification of multiwalled carbon nanotubes (MWCNT) on polypropylene (PP) based nanocomposites is reported. Melt annealing markedly improved the filler dispersion in PP. The rheological and electrical percolative threshold was achieved at a content of 3Â wt% MWCNT, due to the dynamic reconstruction of nanotube network in the polymer matrix. This behaviour was particularly evident in the case of surface-modified MWCNT. However, the heat treatment also induced an overall worsening of mechanical properties due to polymer heterogeneous oxidation at a microscopic scale, as detected by oxygen mapping through SEM/EDS. Crack initiation sites eventually leading to the failure of the polymer were formed due to peroxide-mediated spreading of oxidation, radiating from residual polymerisation catalyst particles. FTIR-ATR spectroscopy demonstrated that blooming of the phenol stabilizer due to thermal annealing was responsible for early oxidation of polypropylene. The reported results highlight the advantages and drawbacks of physical strategies designed to improve the dispersion stability of nanotubes in polymer nanocomposites.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Organic Chemistry
Authors
Gennaro Gentile, Veronica Ambrogi, Pierfrancesco Cerruti, Rosa Di Maio, Giuseppe Nasti, Cosimo Carfagna,