**4.3 X-ray diffraction analysis (XRD)**

X-ray diffraction patterns of all studied samples are shown in **Figure 3**.

In order to provide a more effective visualization of involved samples, as well as their behavior in the present study, components were separated into individual graphs, according to **Figures 4-7**, as follows.


#### **Table 3.**

*Use of Gamma Radiation Techniques in Peaceful Applications*

**(ATR-FTIR)**

4000–650 cm<sup>−</sup><sup>1</sup>

range.

**3.6 Tensile and elongation at break**

relative humidity, for 24 h, prior to testing.

lizing from melt, are shown in **Figure 1**.

**4.1 Differential scanning calorimetric analyses (DSC)**

*Melting and crystallization curves for PLA, PBAT, and PLA/PBAT (50/50).*

**4. Results and discussion**

**3.5 Attenuated total reflection Fourier-transform infrared spectroscopy** 

FTIR is a sensible method for identifying chemical modification in a material and, so, is capable to detect chemical modifications in a polymeric material. This method detects vibrational movements imparted from chemical bonds for the material that is being analyzed. As each chemical group absorbs vibrational energy at a given value, it is possible to differentiate them via infrared spectrum. Spectra were obtained from a PerkinElmer, universal ATR sampling accessory spectrum 100 FTIR spectrometer. Setup collection sample was adjusted for 64 scans, within a

Tensile and elongation at break essay are relevant instruments for evaluating loss of properties and evolution of degradative process of the polymer. Parameters that contribute for mechanical behavior of polymers are chemical structure, crystallinity degree, molar mass, moisture, and reinforcing agent present, among others. All these properties are modified during degradation processes. In case of reinforcing agents, the concentration is not changed; nevertheless, their interaction can be modified in consequence of chemical modifications suffered by the polymer. Tensile and elongation at break tests were accomplished at 25 ± 5°C, in an EMIC

dance with ASTM D 638-14. Specimens were conditioned at 25 ± 5°C and 50 ± 5%

DSC heating curves of PLA, PBAT, and PLA/PBAT (50/50) blends, after crystal-

PLA was primarily amorphous when it was cooled from melt, and this result

suggests that PLA was not able to crystallize within the cooling time frame.

, in accor-

model DL 300 universal essay machine, 20 kN load cell, 50 mm min<sup>−</sup><sup>1</sup>

**144**

**Figure 1.**

*Thermal properties of materials studied.*

**Figure 2.** *TG and DTG curves for PLA, PBAT, and PBAT/PLA (50/50).*

**Figure 4.**

*DRX diffractograms of basic components: PBAT, PLA, CaCO3, and PLA gamma-radiated at 150 kGy.*

In general, the sample is composed by crystals and amorphous phases: the sharp peaks are related to crystallite diffraction, and larger peaks are related to amorphous phases. In **Figure 4**, pure PBAT and PLA exhibited four peaks in 17.5, 20.5, 22.5, and 24.5°, in which 22.5° 2θ was the most intense. Bio-CaCO3 exhibited the most intense peak at 30.0 2θ, among other crystalline ones. PLA gamma-irradiated at 150 kGy exhibited two peaks at 20.0 and 22.0, 2θ, proving the efficacy of gamma irradiation treatment.

PBAT/PLA blends, 82/18 and 65/35, corresponding to **Figures 5** and **6**, respectively, as well as their composites, exhibited two intense peaks at 22.5 and 30.0 2θ, emphasizing that composites showed a higher intensity for peaks than based blends.

PBAT/PLA blend (50/50) and its composite showed just one intense peak at 30.0 2θ, much more intense for corresponding composite.

#### **4.4 Scanning electron microscopy (SEM)**

The cell morphology of all formulations processed using SEM is shown in **Figures 8** and **9**. Images were taken in a 100 × magnification, confirming structural foam nature [45].

**147**

**Figure 6.**

*gamma-radiated at 150 kGy.*

**Figure 5.**

*gamma-radiated at 150 kGy.*

mens are shown.

*Study of Bio-Based Foams Prepared from PBAT/PLA Reinforced with Bio-Calcium Carbonate…*

*DRX diffractograms of PBAT/PLA (82/18) and their compositions with 10 phr of CaCO3 and 5 phr of PLA* 

The higher PBAT concentration in PLA/PBAT blends, the easier will be the miscibility between both PBAT and PLA, as shown in **Figure 8**; in **Figure 9** pure

*DRX diffractograms of PBAT/PLA (65/35) and their compositions with 10 phr of CaCO3 and 5 phr of PLA* 

Addition of PLA gamma-irradiated at 150 kGy contributed for an effective distribution of bio-calcium carbonate 125 μm reinforcement in PBAT/PLA compo-

In **Figure 11** foamed samples obtained from 4 mm die extruder and final speci-

*sea-phase* type morphology, as can be observed in **Figure 9a** and **b**.

sitions and buildup of structural foams, as can be seen in **Figure 10**.

PLA shows an irregular dispersion and PBAT a continuous phase in blends; that is, PLA has a typical and irregular morphology *island-phase* type and the PBAT a

PLA and PBAT micrographs are presented.

*DOI: http://dx.doi.org/10.5772/intechopen.85462*

*Study of Bio-Based Foams Prepared from PBAT/PLA Reinforced with Bio-Calcium Carbonate… DOI: http://dx.doi.org/10.5772/intechopen.85462*

#### **Figure 5.**

*Use of Gamma Radiation Techniques in Peaceful Applications*

In general, the sample is composed by crystals and amorphous phases: the sharp

PBAT/PLA blends, 82/18 and 65/35, corresponding to **Figures 5** and **6**, respectively, as well as their composites, exhibited two intense peaks at 22.5 and 30.0 2θ, emphasizing that composites showed a higher intensity for peaks than based blends. PBAT/PLA blend (50/50) and its composite showed just one intense peak at 30.0

The cell morphology of all formulations processed using SEM is shown in **Figures 8** and **9**. Images were taken in a 100 × magnification, confirming structural

peaks are related to crystallite diffraction, and larger peaks are related to amorphous phases. In **Figure 4**, pure PBAT and PLA exhibited four peaks in 17.5, 20.5, 22.5, and 24.5°, in which 22.5° 2θ was the most intense. Bio-CaCO3 exhibited the most intense peak at 30.0 2θ, among other crystalline ones. PLA gamma-irradiated at 150 kGy exhibited two peaks at 20.0 and 22.0, 2θ, proving the efficacy of gamma

*DRX diffractograms of basic components: PBAT, PLA, CaCO3, and PLA gamma-radiated at 150 kGy.*

**146**

foam nature [45].

irradiation treatment.

**Figure 4.**

**Figure 3.**

*DRX diffractograms of all studied samples.*

2θ, much more intense for corresponding composite.

**4.4 Scanning electron microscopy (SEM)**

*DRX diffractograms of PBAT/PLA (82/18) and their compositions with 10 phr of CaCO3 and 5 phr of PLA gamma-radiated at 150 kGy.*

#### **Figure 6.**

*DRX diffractograms of PBAT/PLA (65/35) and their compositions with 10 phr of CaCO3 and 5 phr of PLA gamma-radiated at 150 kGy.*

The higher PBAT concentration in PLA/PBAT blends, the easier will be the miscibility between both PBAT and PLA, as shown in **Figure 8**; in **Figure 9** pure PLA and PBAT micrographs are presented.

PLA shows an irregular dispersion and PBAT a continuous phase in blends; that is, PLA has a typical and irregular morphology *island-phase* type and the PBAT a *sea-phase* type morphology, as can be observed in **Figure 9a** and **b**.

Addition of PLA gamma-irradiated at 150 kGy contributed for an effective distribution of bio-calcium carbonate 125 μm reinforcement in PBAT/PLA compositions and buildup of structural foams, as can be seen in **Figure 10**.

In **Figure 11** foamed samples obtained from 4 mm die extruder and final specimens are shown.

**Figure 7.**

*DRX diffractograms of PBAT/PLA (50/50) and their compositions with 10 phr of CaCO3 and 5 phr of PLA gamma-radiated at 150 kGy.*

#### **Figure 8.**

*SEM micrographs of PLA/PBAT blends, 100 X magnification: (a) PBAT/PLA, 82/18; (b) PBAT/PLA, 65/35; (c) PBAT/PLA, 50/50.*
