Differential thermal analysis lignin

Tang, W. K., H. W. Eickner. Effect of Inorganic Salts on Pyrolysis of Wood, Cellulose, and Lignin Determined by Differential Thermal Analysis FPL Research Paper 82, U.S.D.A., 1967. 

Figure 1.2. Differential thermal analysis for the humic acid fraction isolated in NaOH from a sapric histosol (1), from the acid precipitate isolated from products of the reaction of meth-ylglyoxal with glycine (2), and from the acid precipitate formed from the reaction of glucose with glycine (3), alkali lignin (4), casein (5), lignin-casein 3 1 complex (6), and lignin-casein 6 1 complex (7).

Thermogravimetry (TG), differential thermal analysis (DTA), and differential scanning calorimetry (DSC) are the most frequently used techniques in lignin chemistry, although thermomechanical analysis (TMA) has also been used effectively in the analysis of thermal properties of lignin (Goring 1963). In this section, the principles of TG, DTA, and DSC, and their application to lignin are described. 

Figure 3. Differential thermal analysis of untreated wood, cellulose, and lignin run in an oxygen atmosphere.

Figure 14, Differential thermal analysis of wood (top), cellulose (middle), and lignin (bottom) treated with 8% sodium tetraborate decahyarate run in oxygen atmosphere (47).

Irvine, G.M. The glass transitions of lignin and hemicellulose and their measurements by differential thermal analysis. TAPPI 67(5), 118-121 (1984)... 

Geoffrey, M.I., 1984. The glass transition of lignin and hemicellu-lose and their measurement by differential thermal analysis. Wood Chem., 67(5) 118-121. 

Ramiah M.V. Thermogravimetric and differential thermal analysis of cellulose, hemicellulose and lignin. JAppl Polym Set. 1970, 14 (6), 1323-1337. 

Hatakeyama T, Nakamura K, Hatakeyama H (1978) Differential thermal analysis of styrene derivatives related to lignin. Polymer 19 593-594... 

Harris EE, Adkins H (1938) Reactions of hydrogen with lignin Pap Trade J 107(20) 38-40 Hatakeyama H, Kubota K, Nakano J (1972) Thermal analysis of lignin by differential scanning calorimetry Cellul Chem Technol 6 521-529... 

There are several reports in the literature describing the effect of chemical structure on the observed thermal properties of lignin. " In the thermal processing of lignin for structural applications, the relationship between chemical structure and thermal properties is of extreme importance. Differential scanning calorimetric (DSC) analysis of HKL and SKL is shown in Fig. 3. The glass transition temperature (Tg) of the HKL appears at 93 "C, much lower than that of the SKL, ID C. 

Transient infrared spectroscopy (TIRS) is a mid-infrared technique [82] that has been developed to obtain spectra of moving solids and viscous liquids. TIRS spectra are obtained from the generation of a thin, short-lived temperature differential that is introduced by means of either a hot or cold jet of gas. When a hot jet is used, an emission spectrum is obtained from the thin, heated surface layer. This technique is known as transient infrared emission spectroscopy (TIRES). When a cold jet is used, the blackbody-like thermal emission from the bulk of the sample is selectively absorbed as it passes through the thin, cooled surface layer. The result is a transmission spectrum convoluted with the observed thermal spectroscopy. This method is known as transient infrared transmission spectroscopy (TIRTS). TIRS is ideally suited for online analysis because it is a single-ended technique that requires no sample preparation. This technique has been applied to the lignin analysis of wood chips [83]. 

The thermal property of sisal fiber was studied at AMPRI Bhopal using the Mettler Toledo STAR System by thermo gravimetric curve and differential thermo gravimetric curve, as shown in Fig. 22.6a, b. The temperature range used for analysis was from 500°C to 800°C. Results revealed that in the temperature range of 50°C-200°C, dehydration as well as degradation of lignin occurred. But, at... 

Earlier, Yi et al. studied the thermal properties of sisal fiber by thermo gravimetric curves and thermo gravimetric differential curves in thermal process. The temperature used for the analysis by this author was 30-600°C. It is reported that dehydration as weU as degradation of lignin occurs in the temperature range from 60 to 200 C. As reported in the present study carried out by AMPRI, Bhopal, almost similar thermal properties of sisal fiber were recorded [92, 151],... 

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