**Abstract**

Graphene has exceptional mechanical capabilities, making it a potential reinforcement material for polymer composites. It also has unique electrical and thermal properties, making it an appealing filler for multifunctional composites, particularly polymer matrix composites, due to its vitality and superior mechanical qualities. This chapter thoroughly examines current graphene research trends, focusing on graphenebased polymer nanocomposites, manufacturing, characteristics and applications. Graphene-based materials are single- or multi-layer platelets that may be mass produced using chemical, physical and mechanical processes. A range of technologies for producing graphene-based materials, as well as methods for dispersing these nanoparticles in different polymer matrices, are being examined. The electrical, mechanical and thermal properties of these nanocomposites are also discussed, as well as how each of these features is influenced by the inherent properties of graphene-based materials and their state of dispersion in the matrix. It follows with a review of graphene's effect on composites and the difficulty of satisfying future industrial requirements.

**Keywords:** composites, graphene oxide, reduced graphene oxide, pristine graphene, polyethylene, polypropylene, thermal stability

## **1. Introduction**

Graphene-reinforced polymer is classified as a multiphase material containing a single type of polymer, copolymer or a blend of polymers with nanofillers or nanoparticles (with dimensions of 1–50 nm) incorporated into the polymer matrix. This considerably affects the different physical, chemical and mechanical properties.

The plurality of the study has concentrated on polymer nanocomposites based on nanofillers: pristine graphene (G), reduce graphene oxide (rGO) and graphene oxide (GO), intending to improve the polymer's electrical, mechanical, thermal and gas barrier properties [1, 2]. Recently, graphene has shown the greatest promise as a nanofiller due to its superior exceptional physical properties. This has created a novel category of polymeric nanocomposites. Graphene, a novel type of carbon, is a one-atom thick plane in a two-dimensional sheet formed of sp2 hybridized carbon atoms arranged in a hexagonal crystalline structure. It is the thinnest recognized material at present [3, 4]. In addition, it is one of the distinct allotropes of carbon that is the basic block to building all

#### **Figure 1.**

*Source of all graphitic forms. Graphene is a 2D building material for carbon materials of all other dimensionalities. It can be made into Buckyballs, 1D nanotubes or to 3D graphite [5].*

graphitic derivative forms shown in **Figure 1**. Graphene can be arranged and stacked in each layer into graphite with three dimensions (3D), rolled into carbon nanotubes with one dimension (1D) and wrapped into fullerene with zero dimensions (0D). Graphene with two dimensions (2D) has distinct physical, chemical and engineering properties, with a large surface area, high thermal stability, electrical and thermal conductivity and high stiffness. These unique features make graphene a promising nanofiller in the field of polymer nanocomposites. As well it exhibits great potential for many applications in different fields such as electronic, medical and engineering [6–10]. Polyolefin (PO) nanocomposites based on nanofillers offer many opportunities to improve and develop the POs, with just small loud amounts of nanofillers. Recently, graphene has been explored for use as a promising nanofiller for POs. Many published articles demonstrate that graphene can be used for the reinforcement of polyolefins due to its exceptional physical and mechanical characteristics [11, 12]. The polyolefin/graphene nanocomposite is still in the early steps of development and improvement. However, the enormous possibilities of this material have become obvious in different research fields including automotive, electronics, and recently, gas and water barrier applications. The main challenge to completely exploiting graphene/polyolefin composites is to achieve a high level of homogeneous dispersion of graphene for the maximum benefit [13].

## **2. Introduction to graphene-reinforced polymer nanocomposites**

Nanotechnology is used in many fields with applications ranging widely from medical to construction. The unique feature of this technology is its size. Materials

#### *Graphene Reinforced Polymer Matrix Nanocomposites: Fabrication Method… DOI: http://dx.doi.org/10.5772/intechopen.108125*

with nano size have distinct characteristics such as a high surface area with low surface defects, which impacts significantly upon the characteristics of the consequent material. To illustrate, in nanotechnology, composites can be used as materials filler to decrease the weight of composite and increase the composite stiffness and fire resistance.

Nanocomposites are extensively used in different applications, e.g. solar cells, transport, construction and several other new implementations because of their unusual properties. They present superior mechanical and thermal properties, whilst being lightweight, characteristics which are complicated to obtain separately from the parent components. Nanocomposites, compared to classic composites, have a nanosize dimension and an exclusive set of characteristics because of their nano size. Consequently, this modern type of material presents progressive technological opportunities. Recently, a significant research body has focused on polymer nanocomposites both in the engineering and scientific fields to explore the distinctive properties of the nanosize system. It offers a sustainable alternative to classical loaded polymers, by adding nanofillers that have a high surface area to a polymer host matrices substance. The poor performance of most polymers can be enhanced to meet the needs and requirements of a wide range of scientific and engineering applications. In polymer nanocomposites, various categories of polymers, such as thermoplastics, thermosets and elastomers can be used as materials matrices. However, thermoplastic-based nanocomposites are attracting the most attention from both academic and industrial sources, due to their potential to be recyclable. The thermomechanical recycling procedure is the most cost-effective process for large scales of polymers. Throughout the thermomechanical recycling process, polymers undergo several kinds of thermal and mechanical processes that could change the polymer molecular structure, consequently changing the polymer performance. Recycled polymers usually have lower performance compared to original polymers, especially in applications that require low-strength polymers. The added nanofillers such as graphene have the potential to improve the properties of the polymer even after recycling [14].

#### **2.1 Nanotechnology**

Nanotechnology refers to materials and devices with design, characterization, production and application at a nanometer scale. Nano is a Greek word that means dwarf, indicating a decrease of size or time, 10<sup>9</sup> fold, that is smaller than a micron by 1000 times. One cubic nanometer (nm3 ) is approximately 20 times the volume of an individual atom. A nanoelement's size relative to a basketball is the same as a basketball's size compared to the earth. These nanoscale materials display at least one unique feature because of their nanoscale size. A high-surface area and quantum effects from the nanosize material contribute to improving the materials by reinforcing their reactivity, and thermal, electrical and mechanical properties. Nanoscience studies the structure and properties of materials at atomic and molecular levels, based on the dimensions of the materials [15].

#### **2.2 Nanoparticles**

Particles with one dimension at least, that is around 1000 nm (1 micron) and less, and possibly as atomic size and molecular length scales (0.2 nm), are termed nanoparticles. Nanoparticles can take both crystalline and amorphous forms and have a high-surface area per unit of volume. That unique property offers greater chemical

reactivity than any other particles with a larger size, even with the same surface. To a certain degree, nanoparticulate material should be considered a featured state of the material, in addition to solid, liquid, gas and plasma states, because of its unique features with a large surface area. Typical nanoparticle crystalline forms are fullerenes and carbon nanotubes, while conventional crystalline forms are graphite and diamond. The materials formed from nanoparticles offer unfamiliar characteristics compared to conventional bulk materials. Many researchers limit the size of nanomaterials to around 50 nm [16] or 100 nm [17]. This maximum limit is justified by the actuality that some physical properties of nanoparticles equal those of bulk particles when their size reaches these values. However, a fair definition extends this upper limit, so that many particles up to 1 micron are classified as nanoparticles [18].
