Few layer graphene-polypropylene nanocomposites: The role of flake diameter

Authors: Vallés, C., Abdelkader, A.M., Young, R.J. and Kinloch, I.A.

Journal: Faraday Discussions

Volume: 173

Pages: 379-390

eISSN: 1364-5498

ISSN: 1359-6640

DOI: 10.1039/c4fd00112e

Abstract:

Graphene shows excellent potential as a structural reinforcement in polymer nanocomposites due to its exceptional mechanical properties. We have shown previously that graphene composites can be analysed using conventional composite theory with the graphene flakes acting as short fillers which have a critical length of ∼3 μm which is required for good reinforcement. Herein, polypropylene (PP) nanocomposites were prepared using electrochemically-exfoliated few layer graphene (FLG) with two different flake diameters (5 μm and 20 μm). The crystallization temperature and degree of crystallinity of the PP were found to increase with the loading of FLG, which suggests that the flakes acted as crystallisation nucleation sites. Mechanical testing showed that the 5 μm flakes behaved as short fillers and reinforced the PP matrix poorly. The modulus of the 20 μm flake composites, however, increased linearly with loading up to 20 wt%, without any of the detrimental aggregation effects seen in other graphene systems. The mechanical data were compared with our previous work on other graphene composite systems and the apparent need to balance the degree of functionalization to improve matrix compatibility whilst not encouraging aggregation is discussed.

Source: Scopus

Few layer graphene-polypropylene nanocomposites: the role of flake diameter.

Authors: Vallés, C., Abdelkader, A.M., Young, R.J. and Kinloch, I.A.

Journal: Faraday Discuss

Volume: 173

Pages: 379-390

ISSN: 1359-6640

DOI: 10.1039/c4fd00112e

Abstract:

Graphene shows excellent potential as a structural reinforcement in polymer nanocomposites due to its exceptional mechanical properties. We have shown previously that graphene composites can be analysed using conventional composite theory with the graphene flakes acting as short fillers which have a critical length of ∼3 μm which is required for good reinforcement. Herein, polypropylene (PP) nanocomposites were prepared using electrochemically-exfoliated few layer graphene (FLG) with two different flake diameters (5 μm and 20 μm). The crystallization temperature and degree of crystallinity of the PP were found to increase with the loading of FLG, which suggests that the flakes acted as crystallisation nucleation sites. Mechanical testing showed that the 5 μm flakes behaved as short fillers and reinforced the PP matrix poorly. The modulus of the 20 μm flake composites, however, increased linearly with loading up to 20 wt%, without any of the detrimental aggregation effects seen in other graphene systems. The mechanical data were compared with our previous work on other graphene composite systems and the apparent need to balance the degree of functionalization to improve matrix compatibility whilst not encouraging aggregation is discussed.

Source: PubMed

Few layer graphene-polypropylene nanocomposites: the role of flake diameter

Authors: Valles, C., Abdelkader, A.M., Young, R.J. and Kinloch, I.A.

Journal: FARADAY DISCUSSIONS

Volume: 173

Pages: 379-390

eISSN: 1364-5498

ISSN: 1359-6640

DOI: 10.1039/c4fd00112e

Source: Web of Science (Lite)

Few layer graphene-polypropylene nanocomposites: the role of flake diameter.

Authors: Vallés, C., Abdelkader, A.M., Young, R.J. and Kinloch, I.A.

Journal: Faraday discussions

Volume: 173

Pages: 379-390

eISSN: 1364-5498

ISSN: 1359-6640

DOI: 10.1039/c4fd00112e

Abstract:

Graphene shows excellent potential as a structural reinforcement in polymer nanocomposites due to its exceptional mechanical properties. We have shown previously that graphene composites can be analysed using conventional composite theory with the graphene flakes acting as short fillers which have a critical length of ∼3 μm which is required for good reinforcement. Herein, polypropylene (PP) nanocomposites were prepared using electrochemically-exfoliated few layer graphene (FLG) with two different flake diameters (5 μm and 20 μm). The crystallization temperature and degree of crystallinity of the PP were found to increase with the loading of FLG, which suggests that the flakes acted as crystallisation nucleation sites. Mechanical testing showed that the 5 μm flakes behaved as short fillers and reinforced the PP matrix poorly. The modulus of the 20 μm flake composites, however, increased linearly with loading up to 20 wt%, without any of the detrimental aggregation effects seen in other graphene systems. The mechanical data were compared with our previous work on other graphene composite systems and the apparent need to balance the degree of functionalization to improve matrix compatibility whilst not encouraging aggregation is discussed.

Source: Europe PubMed Central