A Study of Reaction Mechanisms by DSC and TG

Arseneau, Donald F.; Stanwick, J. J. J.

doi:10.1007/978-3-0348-5775-8_28

Cited by 4 publications

(2 citation statements)

References 2 publications

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“…The char is generally not pure carbon, and other gases, such as CO 2 , could equally well be evolved during the charforming step (they are certainly evolved during pyrolysis itself). Nevertheless, the char-forming process has been characterized by some workers as involving mainly a dehydration, in accord with this highly simplified model (Kilzer and Broido, 1965;Broido, 1966;Broido and Weinstein, 1970;Broido and Nelson, 1975;Arsenau, 1971;Arseneau and Stanwick, 1971;Bradbury et al, 1979). Though some features of such simple cellulose pyrolysis models have been the subject of recent challenge (Varhegyi et al, 1994), the basic feature of a competitive pathway leading to differing yields of char has been upheld.…”

Section: Resultsmentioning

confidence: 99%

Thermal Effects in Cellulose Pyrolysis: Relationship to Char Formation Processes

Milosavljevic

Oja

Suuberg

1996

Ind. Eng. Chem. Res.

273

178

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The thermochemistry of cellulose pyrolysis has been studied by a combination of differential scanning calorimetry and thermogravimetric analysis. Additionally, the vapor pressure and heat of vaporization of levoglucosan have been determined by an effusion method. The cellulose pyrolysis has been carried out under inert gas at heating rates from 0.1 to 60 K/min. The main cellulose thermal degradation pathway is endothermic, in the absence of mass transfer limitations that promote char formation. The endothermicity is estimated to be about 538 J/g of volatiles evolved. It is concluded that this endothermicity mainly reflects a latent heat requirement for vaporizing the primary tar decomposition products. Pyrolysis can be driven in the exothermic direction by char-forming processes that compete with tar-forming processes. The formation of char is estimated to be exothermic to the extent of about 2 kJ/g of char formed. Low heating rates, in concert with mass transfer limitations, serve to drive the pyrolysis in this direction. The enthalpy of cellulose pyrolysis is thus seen to be a sensitive function of the pyrolysis conditions. Pyrolysis appears to initially follow a common thermal pathway (in terms of enthalpy required per mass of volatile loss), irrespective of heating rate. Only at some finite level of conversion does the “thermal trajectory” of the process follow a heating rate dependent path, as significant char formation begins to occur.

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Section: Resultsmentioning

confidence: 99%

Thermal Effects in Cellulose Pyrolysis: Relationship to Char Formation Processes

Milosavljevic

Oja

Suuberg

1996

Ind. Eng. Chem. Res.

273

178

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“…At 10% or higher PEG concentration, the finished ramie fabrics showed even less %residue than untreated ramie. Note that this low %residue occurred with high %add-on of ramie treated with glyoxal and PEG600 (Table IV [2]. This indicates that TGA can be used as a potential tool for determining the presence of PEG on glyoxal-treated materials.…”

Section: Discussionmentioning

confidence: 87%

Nonformaldehyde Crease-Resistant Finishing of Ramie with Glyoxal in the Presence of a Swelling Agent

Jung

Choi

2001

Textile Research Journal

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The feasibility of glyoxal treatment for ramie fabric in the presence of a swelling agent is studied. Adding polyethylene glycol (PEG) 600 or a higher molecular weight PEG to the glyoxal finishing bath provides an optimum balance between the wrinkle recovery angle and strength retention by maximizing ramie swelling during the crosslinking reaction. Adding PEG also increases the water of imbibition, moisture regain, whiteness index, and color strength of treated ramie fabrics. The durability of glyoxal finished fabric in the presence of PEG is also acceptable during multiple launderings. Therefore, glyoxal treatment with PEG can be used for crease-resistant finishing of ramie and ramie-blended fabrics to obtain superior performance properties.

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The pyrolysis of cellulose derivatives

Brown

Tipper

1978

J of Applied Polymer Sci

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SynopsisThe thermal degradation in uucuo of ethyl cellulose and cellulose acetate in the form of very thin films or bulk material between 230° and 32OOC has been studied. With the ethyl cellulose films, volatilization (as measured by weight loss) was a first-order process up to about 50% reaction, with an activation energy of 208 kJ/mole. This is about the same as that associated with the initial drop in intrinsic viscosity of the solid during bulk pyrolysis, in which very high molecular weight material, probably crosslinked, was formed at a later stage. The volatile products from ethyl cellulose included HzO, CO, COz, C2H4, C2H6, CzHbOH, CH3CH0, unsaturated aliphatic compounds, and furan derivatives. Acetic acid and acetyl derivatives of D-glucose were produced from cellulose acetate. It is suggested that the polymers degrade by radical chain mechanisms, and a number of possible elementary steps are proposed.

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A Study of Reaction Mechanisms by DSC and TG

Cited by 4 publications

References 2 publications

Thermal Effects in Cellulose Pyrolysis: Relationship to Char Formation Processes

Thermal Effects in Cellulose Pyrolysis: Relationship to Char Formation Processes

Nonformaldehyde Crease-Resistant Finishing of Ramie with Glyoxal in the Presence of a Swelling Agent

The pyrolysis of cellulose derivatives

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