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Compatibilized polypropylene nanocomposites containing expanded graphite and graphene nanoplatelets
Author(s) -
Ho Quang Binh,
Kontopoulou Marianna
Publication year - 2021
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.25647
Subject(s) - materials science , polypropylene , exfoliation joint , compatibilization , composite material , graphite , nanocomposite , percolation threshold , graphene , compounding , flexural strength , surface modification , chemical engineering , polymer , copolymer , electrical resistivity and conductivity , polymer blend , nanotechnology , engineering , electrical engineering
We present a non‐covalent compatibilization approach to prepare polypropylene (PP) composites containing expanded graphite (EG) and graphene nanoplatelets (GNPs) by melt compounding. This method involves PP matrix functionalization with pyridine (Py) moieties, which are capable of engaging in π‐π interactions with the surface of the EG and GNPs. The addition of 10 wt% of PP grafted with amino‐pyridine (PP‐g‐Py) to neat PP facilitated the break‐up of EG particles, by intercalating between their layers and facilitating their separation into smaller tactoids. GNPs were prepared starting from EG through a thermomechanical exfoliation method. Addition of GNPs to PP resulted in well‐dispersed platelets having aspect ratios as high as 40, whereas in the presence of the PP‐g‐Py compatibilizer the matrix contained sub‐micron scale platelets. The electrical percolation thresholds were in the vicinity of 6 and 10 vol% in the compatibilized PP‐EG and PP‐GNP composites, respectively, and the maximum value of the electrical conductivity achieved was 10 −1 S/m for the compatibilized GNP composites. Addition of GNPs resulted in increases in the flexural moduli by as much as 95% compared to the unfilled PP, whereas the impact strength remained unaffected up to 10 wt% GNP content.