**4.1. Thermogravimetric analysis (TGA) and derivative thermogravimetric (DTG)**

Thermogravimetric analysis (TGA) is a useful method for the quantitative determination of the degradation behaviour and the composition of particular material. The magnitude and location of the curve in thermograms provides the information of the component and the interaction between the components at various temperature scales [57]. The chemistry of bamboo is complex and has been divided by analytical methods into major components including cellulose, hemicellulose and lignin like several other lignocellulosic materials [58, 59]. Under these circumstances, the thermal decomposition is somewhat similar to the combination of those of the constituents pyrolyzed at the same conditions.

one very broad peak [70, 71]. Other study has reported thermogravimetric study on alkaline treated *Bamboosa balcua* both in strip and dust form. They observed that thermograms of untreated bamboo exhibited two steps of degradation in wide range between 50–150 and 426– 150°C, respectively. The first step of degradation, 7.65% weight loss was assigned to moisture evaporation and variation in trend in weight loss was observed in treated samples depending upon concentration of alkaline used. It was found that with increase in concentration of alkaline the amount of moisture absorbed was decreased, which was evident from TGA curves. This observation was supported on the basis of crystallinity index [72]. The tendency to release absorbed moisture upon heating will decrease as water is strongly attached in a well

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Typical TGA curves determined and reported by researchers can be illustrated by **Figure 3**. Apart from this, the thermal degradation process of bamboo fiber reinforcement was studied by Rajulu et al. [73] and it was stated that the thermal degradation of the fibers follow a two stage process. The TGA curves obtained might due to the fact that bamboo is composed of a strong composite network, which is interlinked through inter and intramolecular hydrogen bonding between polyphenolic groups lignin, hemicelluloses and α-cellulosic components of this network. The second degradation temperature region corresponds to hemicellulose

A study on different hemicellulosic subfractions of *Phyllostachys bambusoides* by Peng et al. [76] to explore the mass loss and compare thermal behavior of different fraction was carried out. It was observed that weight loss of among two isolated fractions (HA and H45) mainly occurred in the range of 200–320°C and was found that HA fraction was more thermally stable than H45, indicating that hemicelluloses exhibited more thermal stability than branched hemicelluloses. This observation was supported by DTG studies, where the DTG curves exhibited

**Figure 3.** TGA thermograms of (A) raw, pulp, bleached, and pressurized enzyme hydrolysis bamboo fibers [74]; and (B) thermal analysis of green bamboo fiber, dewaxed bamboo fiber, delignified bamboo fiber and cellulose fiber [75].

packed structure leading to higher finished temperature.

degradation present in bamboo fiber.

In a study by Tamizi [31] on different species of bamboo (*Gigantochloa*), viz., *G. brang* and *G. levis*, TGA studies were carried out at different positions which designated as outer, middle and inner layer. The shape of thermograms in these two species revealed quite similar characteristics. The behavior was in agreement with the data obtained by other researchers. Xie et al. [60] and Mui et al. [61] reported that the temperature range, weight losses and the rates of thermal degradation at different stages (devolatilization and combustion steps) changes with each different fiber at any specific location of the plant [62]. Thermal stability was observed up to 210°C in *G. brang* and thereafter started to decompose.

The initial degradation temperature between 210 and 390°C are linked to decomposition of bamboo constituents, which are mainly cellulose and hemicellulose [63, 64]. The second stage degradation between 390 and 800°C in the entire sample corresponds to decomposition of lignin. Previous studies have shown that the thermal stability is determined by the chemical composition of any biomass as various components of lignocellulosic materials have different thermal behaviors [62, 65]. Also, several studies on the thermal decomposition of the individual components of lignocellulosic materials indicated that decomposition of hemicellulose starts first, followed by the cellulose and finally, the lignin [65–68]. Similarly, in the thermograms of *G. levis,* samples gave an initial weight loss below 100°C attributed to the loss of moisture. Thereafter, the thermal degradation of the bamboo samples starts to decompose near 200°C at both internode and nodes. A distinct weight loss was observed between 230–400 and 230–390°C at the internode and node, respectively.

Differential thermograms revealed that different mass losses due to different constituents present at different positions. From DTG curves, it can be concluded that two major processes took place when *G. brang* decomposed. It was observed that a minor weight loss occurred below 100°C, with peaks between temperatures of 25 and 105°C. These weight losses have been reported to be associated loss of water as a moisture evaporation process [65]. The main DTG peak was assigned to the decomposition of hemicellulose and cellulose [69]. The decomposition of lignin is indicated by clear wide tail due to devolatilization process [63]. In presence of nitrogen, it has been observed that mass loss of small biomass samples at lower heating rates usually produce one to two major distinct DTG peaks, corresponding to hemicellulose and cellulose pyrolysis. For example, Font et al. [70] inspected the thermal decomposition of almond shells at 10°C min−1 in the inert atmosphere, resulting in two not completely separate DTG peaks, with one centering at around 310°C and other at 368°C.

In another study, one major peak was recorded for degradation of cotton stalk, sugarcane bagasse, rice straw, EFB, etc., under nitrogen while two peaks were reported by the same author for the degradation of these bioresources under oxygen. Thus, changes in the parameters like heating rate and atmospheric condition can sometimes merge the two peaks into one very broad peak [70, 71]. Other study has reported thermogravimetric study on alkaline treated *Bamboosa balcua* both in strip and dust form. They observed that thermograms of untreated bamboo exhibited two steps of degradation in wide range between 50–150 and 426– 150°C, respectively. The first step of degradation, 7.65% weight loss was assigned to moisture evaporation and variation in trend in weight loss was observed in treated samples depending upon concentration of alkaline used. It was found that with increase in concentration of alkaline the amount of moisture absorbed was decreased, which was evident from TGA curves. This observation was supported on the basis of crystallinity index [72]. The tendency to release absorbed moisture upon heating will decrease as water is strongly attached in a well packed structure leading to higher finished temperature.

interaction between the components at various temperature scales [57]. The chemistry of bamboo is complex and has been divided by analytical methods into major components including cellulose, hemicellulose and lignin like several other lignocellulosic materials [58, 59]. Under these circumstances, the thermal decomposition is somewhat similar to the combination of

In a study by Tamizi [31] on different species of bamboo (*Gigantochloa*), viz., *G. brang* and *G. levis*, TGA studies were carried out at different positions which designated as outer, middle and inner layer. The shape of thermograms in these two species revealed quite similar characteristics. The behavior was in agreement with the data obtained by other researchers. Xie et al. [60] and Mui et al. [61] reported that the temperature range, weight losses and the rates of thermal degradation at different stages (devolatilization and combustion steps) changes with each different fiber at any specific location of the plant [62]. Thermal stability was observed up to

The initial degradation temperature between 210 and 390°C are linked to decomposition of bamboo constituents, which are mainly cellulose and hemicellulose [63, 64]. The second stage degradation between 390 and 800°C in the entire sample corresponds to decomposition of lignin. Previous studies have shown that the thermal stability is determined by the chemical composition of any biomass as various components of lignocellulosic materials have different thermal behaviors [62, 65]. Also, several studies on the thermal decomposition of the individual components of lignocellulosic materials indicated that decomposition of hemicellulose starts first, followed by the cellulose and finally, the lignin [65–68]. Similarly, in the thermograms of *G. levis,* samples gave an initial weight loss below 100°C attributed to the loss of moisture. Thereafter, the thermal degradation of the bamboo samples starts to decompose near 200°C at both internode and nodes. A distinct weight loss was observed between 230–400

Differential thermograms revealed that different mass losses due to different constituents present at different positions. From DTG curves, it can be concluded that two major processes took place when *G. brang* decomposed. It was observed that a minor weight loss occurred below 100°C, with peaks between temperatures of 25 and 105°C. These weight losses have been reported to be associated loss of water as a moisture evaporation process [65]. The main DTG peak was assigned to the decomposition of hemicellulose and cellulose [69]. The decomposition of lignin is indicated by clear wide tail due to devolatilization process [63]. In presence of nitrogen, it has been observed that mass loss of small biomass samples at lower heating rates usually produce one to two major distinct DTG peaks, corresponding to hemicellulose and cellulose pyrolysis. For example, Font et al. [70] inspected the thermal decomposition of almond shells at 10°C min−1 in the inert atmosphere, resulting in two not completely separate

In another study, one major peak was recorded for degradation of cotton stalk, sugarcane bagasse, rice straw, EFB, etc., under nitrogen while two peaks were reported by the same author for the degradation of these bioresources under oxygen. Thus, changes in the parameters like heating rate and atmospheric condition can sometimes merge the two peaks into

those of the constituents pyrolyzed at the same conditions.

156 Bamboo - Current and Future Prospects

210°C in *G. brang* and thereafter started to decompose.

and 230–390°C at the internode and node, respectively.

DTG peaks, with one centering at around 310°C and other at 368°C.

Typical TGA curves determined and reported by researchers can be illustrated by **Figure 3**. Apart from this, the thermal degradation process of bamboo fiber reinforcement was studied by Rajulu et al. [73] and it was stated that the thermal degradation of the fibers follow a two stage process. The TGA curves obtained might due to the fact that bamboo is composed of a strong composite network, which is interlinked through inter and intramolecular hydrogen bonding between polyphenolic groups lignin, hemicelluloses and α-cellulosic components of this network. The second degradation temperature region corresponds to hemicellulose degradation present in bamboo fiber.

A study on different hemicellulosic subfractions of *Phyllostachys bambusoides* by Peng et al. [76] to explore the mass loss and compare thermal behavior of different fraction was carried out. It was observed that weight loss of among two isolated fractions (HA and H45) mainly occurred in the range of 200–320°C and was found that HA fraction was more thermally stable than H45, indicating that hemicelluloses exhibited more thermal stability than branched hemicelluloses. This observation was supported by DTG studies, where the DTG curves exhibited

**Figure 3.** TGA thermograms of (A) raw, pulp, bleached, and pressurized enzyme hydrolysis bamboo fibers [74]; and (B) thermal analysis of green bamboo fiber, dewaxed bamboo fiber, delignified bamboo fiber and cellulose fiber [75].

the maximum peak at 296 and 293°C with shoulders at 242 and 237°C, respectively for H<sup>45</sup> fraction. These results were justified by different researchers with different view of explanation. Nowakowski et al. [77] corroborated the first peak with reduced temperature polymerization process leading to the formation of char, carbon monoxide, carbon dioxide and water. Meanwhile, the second peak was assigned to generation of volatile anhydrosugars and related monomeric compounds.

**Author details**

\*, Abdul Khalil H.P.S.

, Asniza Mustapha2

\*Address all correspondence to: samsul.rizal@unsyiah.ac.id

2

, Ikramullah1

1 Department of Mechanical Engineering, Syiah Kuala University, Banda Aceh, Indonesia

3 Faculty of Earth Science, Universiti Malaysia Kelantan, Campus Jeli, Kelantan, Malaysia

[1] Li Y, Yao J, Li R, Zhang Z, Zhang J. Thermal and energy performance of a steel-bamboo

[2] Liese W, Kohl M. Bamboo. New York City, United States: Springer International

[3] Huang Z, Sun Y, Musso F. Assessment of bamboo application in building envelope by comparison with reference timber. Construction and Building Materials. 2017;**156**:844-860

[4] Ling M, Christensen M, Donnison A, Belmonte KD, Brown C. Scoping Study to Inform the Global Assessment of Bamboo and Rattan (GABAR). Cambridge, United Kingdom:

[5] Sánchez ML, Morales LY, Caicedo JD. Physical and mechanical properties of agglomerated panels made from bamboo fiber and vegetable resin. Construction and Building

[6] Li M, Zhou S, Guo X. Effects of alkali-treated bamboo fibers on the morphology and mechanical properties of oil well cement. Construction and Building Materials. 2017;**150**:

[7] Sukmawan R, Takagi H, Nakagaito AN. Strength evaluation of cross-ply green composite laminates reinforced by bamboo fiber. Composites Part B: Engineering. 2016;**84**:9-16

[8] Bahari SA, Krause A. Utilizing Malaysian bamboo for use in thermoplastic composites.

[9] Jakovljević S, Lisjak D, Alar Ž, Penava F. The influence of humidity on mechanical properties of bamboo for bicycles. Construction and Building Materials. 2017;**150**:35-48 [10] Gu X, Deng X, Liu Y, Zeng Q, Wu X, Ni Y, Liu X, Wu T, Fang P, Wang B, Wu Q. Review on comprehensive utilization of bamboo residues. Transactions of the Chinese Society of

2 School of Industrial Technology, Universiti Sains Malaysia, Penang, Malaysia

composite wall structure. Energy and Buildings. 2017;**156**:225-237

United Nations Environment Programme (UNEP); 2016

Journal of Cleaner Production. 2016;**110**:16-24

Agricultural Engineering. 2016;**32**(1):236-242

, Irshad Ul Haq Bhat3

Recent Advancement in Physico-Mechanical and Thermal Studies of Bamboo and Its Fibers

and Chaturbhuj Kumar Saurabh2

, Syifaul Huzni<sup>1</sup>

http://dx.doi.org/10.5772/intechopen.76475

,

159

Samsul Rizal1

**References**

Publishing; 2015

Materials. 2017;**156**:330-339

619-625

Sulaiman Thalib1

Mui et al. [61] reported that three key components of bamboo namely, xylan, cellulose, and lignin has one major decomposition step to volatiles and a minor decomposition to which leads to the formation of char. A well model theory was presented to explain the decomposition of these components from bamboo to volatiles and chars called as five component and six component systems. Different thermo-parameters were obtained by these model systems. Moreover, Krzesinska et al. [78] conducted the thermal studies on solid iron bamboo (*Dendrocalamus strictus*), a bamboo with unique properties. The thermal decomposition of *Dendrocalamus strictus* was studied at different temperatures varying from 300 to 600°C. It was found that in the case of both raw and pre-charred *Dendrocalamus strictus,* poor thermal decomposition is completely absent. These carbonized samples of *Dendrocalamus strictus* would be a bonus for manufacturing of thermally stable composites.
