**5. Materials and methods**

Sodium hydroxide, clay, and banana fiber were the raw materials used for this study.

#### **5.1 Chemical treatment and nanoclay infusion into the banana fiber**

Nanoclay was infused into fibers' in-house cellulose phases using shear-induced force treatment in two phases, which are alkaline (NaOH) and NaOH/clay treatment. Before chemical treatment, fiber was extracted from the banana plant, air-dried for a week, and chopped to a 5 cm uniform length. Similarly, removing unwanted phases before the chopped banana fiber achieved alkaline treatment was soaked, starred slowing in acetone for 30 min, and then oven-dried at 80°C for 120 min.

#### **5.2 Fibers chemical treatment (NaOH)**

Forty grams of dried chopped fiber, 40 grams of sodium hydroxide, and 600 ml of water were measured simultaneously for this process. Then, sodium hydroxide was added to distilled water and stirred at 500 rpm under a controlled temperature of 80°C for 15 min. Afterward, 40 grams of dried chopped fiber were added to the sodium hydroxide solution and stirred for another for 4 h at the same temperature (80°C). Later, the treated fibers were removed from the sodium hydroxide solution and softly washed using running water to remove retaining sodium hydroxide solution or unwanted phases in the fiber to ensure purity. The fiber was then dried at 80°C for 2 h and later used to develop banana fiber-reinforced composite and hybrid.

#### **5.3 Sodium hydroxide/nanoclay treatment**

Montmorillonite (MMT) nanoclay was a shear-induced force into banana fiber using the alkane treatment technique. Forty grams of sodium hydroxide were poured into 600 ml of water and stirred at 500 rpm at a conditional temperature of 80°C for 15 min. After which, 20 grams of Na+ montmorillonite were put into the sodium hydroxide solution and stirred together for 30 min to dissolve the clay particle in the solution. Chopped banana fiber (20 grams) was added to montmorillonite/ sodium hydroxide solution and mixed for another 4 h at 750 rpm under the exact temperature of 80°C. The high stirring speed generates a high shear force generated, which enhance the dispersion of clay particle into fibers. Later, the treated fibers were removed from the montmorillonite/sodium hydroxide solution and softly washed using running water to remove retaining montmorillonite/sodium hydroxide solution or unwanted phases in the fiber to ensure purity. The fiber was then dried at 80°C for 2 h and later used to develop banana fiber-reinforced composite and hybrid.

#### **5.4 Composite development**

The treated and untreated fiber reinforced epoxy resin using conventional resin casting techniques. This process was employed to develop both untreated and

#### *Influence of Loading Nanoclay on Properties of the Polymer-based Composite DOI: http://dx.doi.org/10.5772/intechopen.108478*

treated banana fiber-reinforced composite. The fibers were chopped into different lengths between 30 and 50mm, and fiber with a specific length was incorporated as a reinforcement in the matrix (epoxy resin). This process was aimed to determine the required length and concentration of the fibers treated and untreated for these series and also to identify reinforcement suitability and influence of each fiber length on epoxy resin properties. The determination of critical length is a prerequisite to fiber concentrations in epoxy resin, meaning the fiber volume was committed only when the critical length was discovered.

The conventional resin casting techniques were conducted in two phases. The first phase was mixing fiber and resin, and the second entailed casting fiber/ resin in a mold cavity. The first phase was achieved by measuring 100 grams of epoxy resin into a beaker and heating it to 80°C. Then, a specific concentration with fiber length was added and stirred for 1 hour with a magnetic stirrer at 500 rpm, still at a temperature of 80°C. This blend was removed from the stirrer, allowing it to cool down at ambient temperature for 30 min. A 10:30 mixing ratio of epoxy resin and catalyst, which had the 30%, was adopted. The catalyst mixing ratio of 30 was afterward added to the fiber-resin blend and stirred till homogeneousness was achieved. As mentioned, casting the fiber-resin blend in the mold cavity is the second. This process was achieved by pouring the fiberresin catalyst into the top open-ended Perspex mold sheet gapped with a 3-mm rubber gasket on three sides. The composite cavity was quickly removed after curing by applying wax on the inner part of the mold before pouring fiberresin catalyst. The casted banana fiber-reinforced epoxy resin composite was removed after 48 h, and its properties were investigated after 7 days of the initial casting—the effect of banana fiber distribution during casting on epoxy resin thermomechanical properties.

#### **5.5 Testing**

The thermal behaviors of the fiber and composite were investigated on a thermogravimetry (SDT Q600 model). The heating profile was obtained at a 10 °C/ min heating rate under a dry nitrogen gas flow at 100 mL/min from 0°C to 600°C. Temperature dependence mechanical properties such as storage modulus and tan α were measured on a dynamic mechanical analyzer at a frequency of 10 Hz in a three-point bending mode. This investigation was carried out using the TA equipment (Q800) from room temperature to 100°C under atmospheric conditions. Resistance to pulling stress (tensile strength) and fiber and composite residual strength was investigated using an MTS-UTM machine with a 1 KN load cell. Short beam investigation was used to determine the shear properties of the untreated and treated fiber-reinforced epoxy composite series. This test was carried out in agreement with ASTM 2344-84 standard using a crosshead speed of 1 mm/min. The tensile test was carried out following ASTM D 3039 using an operating speed of 1 mm/min with a 1 KN load cell. The samples investigated were three cubical blocks of 1 cm by 1cm by 1cm cut from banana fiber (treated and untreated) reinforced composite. A fiber pull-out investigation was carried out on samples prepared with 10 cm fiber length entrenched in 3 mm depth in cured epoxy resin, which was subjected to a constant load of 1 kN until a failure occurred. Fiber pull-out strength was determined using the failure ratio on a load-displacement curve. Samples were stressed for both pull-out and tensile strength until the coefficient of variance (CV) was ≤16%.
