Graphene Layers Functionalized with A Janus Pyrrole-Based Compound in Natural Rubber Nanocomposites with Improved Ultimate and Fracture Properties
Open Access
- 18 April 2020
- Vol. 12 (4), 944
- https://doi.org/10.3390/polym12040944
Abstract
The ultimate properties and resistance to fracture of nanocomposites based on poly(1,4-cis-isoprene) from Hevea Brasiliensis (natural rubber, NR) and a high surface area nanosized graphite (HSAG) were improved by using HSAG functionalized with 2-(2,5-dimethyl-1H-pyrrol-1-yl)propane-1,3-diol (serinol pyrrole) (HSAG-SP). The functionalization reaction occurred through a domino process, by simply mixing HSAG and serinol pyrrole and heating at 180 °C. The polarity of HSAG-SP allowed its dispersion in NR latex and the isolation of NR/HSAG-SP masterbatches via coagulation. Nanocomposites, based either on pristine HSAG or on HSAG-SP, were prepared through traditional melt blending and cured with a sulphur-based system. The samples containing HSAG-SP revealed ultimate dispersion of the graphitic filler with smaller aggregates and higher amounts of few layers stacks and isolated layers, as revealed by transmission electron microscopy. With HSAG-SP, better stress and elongation at break and higher fracture resistance were obtained. Indeed, in the case of HSAG-SP-based composites, fracture occurred at larger deformation and with higher values of load and, at the highest filler content (24 phr), deviation of fracture propagation was observed. These results have been obtained with a moderate functionalization of the graphene layers (about 5%) and normal lab facilities. This work reveals a simple and scalable way to prepare tougher NR-based nanocomposites and indicates that the dispersion of a graphitic material in a rubber matrix can be improved without using an extra-amount of mechanical energy, just by modifying the chemical nature of the graphitic material through a sustainable process, avoiding the traditional complex approach, which implies oxidation to graphite oxide and subsequent partial reduction.This publication has 79 references indexed in Scilit:
- Cyclic loadings and crystallization of natural rubber: An explanation of fatigue crack propagation reinforcement under a positive loading ratioMaterials Science and Engineering: A, 2011
- Green strength of natural rubber: The origin of the stress–strain behavior of natural rubberJournal of Applied Polymer Science, 2008
- Factors that Affect the Fatigue Life of Rubber: A Literature SurveyRubber Chemistry and Technology, 2004
- Strain-Induced Crystallization and Strength of RubberRubber Chemistry and Technology, 2002
- Crystallization and Morphology of RubberRubber Chemistry and Technology, 1995
- Fatigue and Fracture of ElastomersRubber Chemistry and Technology, 1995
- Molecular Aspects of the Fatigue and Fracture of RubberRubber Chemistry and Technology, 1994
- Molecular Aspects of TackRubber Chemistry and Technology, 1984
- Tack and Green Strength of Elastomeric MaterialsRubber Chemistry and Technology, 1981
- Tensile Rupture of RubberRubber Chemistry and Technology, 1970