The thermal degradation of cellulose triacetate—I. The reaction products

Scotney, A.

doi:10.1016/0014-3057(72)90092-4

Cited by 29 publications

(6 citation statements)

References 10 publications

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“…The dehydration of cellulose, and the deesterification of CP as well, occur at the C2 and/or C3 positions preferably than do at C6, paralleling a socalled Zaitsev rule (Scotney 1972). A double bond resulting between C2 and C3 can transform into a C=O structure by a keto-enol tautomerism (discussed below).…”

Section: ) ( II )mentioning

confidence: 96%

Phosphorylated cellulose propionate derivatives as thermoplastic flame resistant/retardant materials: influence of regioselective phosphorylation on their thermal degradation behaviour

Aoki

Nishio

2010

Cellulose

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Cellulose ester derivatives having phosphoryl side-chains were synthesized by phosphorylation of two types of cellulose propionate (CP); the difference between the two CPs was whether the primary hydroxyl group at C6 had been fully propionylated or not. Dimethyl phosphate, dimethyl thiophosphate, diethyl phosphate, or diethyl thiophosphate was introduced into the residual hydroxyl positions of the CPs. Chemical composition of the respective derivatives was characterized by elemental analysis and a combined use of saponification and HPLC quantification of the released propionic acid. Their thermal properties were investigated by DSC and TGA, and an intermediate residue of the pyrolysis was also examined by FT-IR spectroscopy. From the thermal degradation measurements using TGA, the C6-O phosphorylation was found to noticeably prevent the CP derivatives from weight loss in the pyrolysis process under dynamic air, i.e., providing them with a flame-resistance functionality, whereas the C2-O and C3-O phosphorylation did not give rise to such an appreciable resistance effect. A discussion was focused on the difference in pyrolysis mechanism between the phosphorylated CPs. However, most samples of the CP derivatives showed a clear T g considerably lower than the onset temperature of the thermal degradation. Thus we suggest that it is possible to design thermoplastic flame resistant/ retardant materials based on cellulose, by controlling the substitution distribution of the phosphoryl and propionyl groups introduced.

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Section: ) ( II )mentioning

confidence: 96%

Phosphorylated cellulose propionate derivatives as thermoplastic flame resistant/retardant materials: influence of regioselective phosphorylation on their thermal degradation behaviour

Aoki

Nishio

2010

Cellulose

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“…The acetyls increase the thermal stability but the acetic acid formation in the course of degradation is probably related to the exotherm starting at 385 °C. The oxidation probably proceeds through the addition of oxygen to double bonds formed by deacetylation (Scotney 1972).…”

Section: Resultsmentioning

confidence: 99%

Thermal Degradation and Thermooxidation of O-Acetyl-(4-O-methyl-D-glucurono)-D-xylan and Related Derivatives

Simkovic¹,

Balog²,

Csomorová³

1995

HFSG

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Four polysaccharide samples related to (4-O-methyl-D-glucurono)-D-xylan were analyzed by thermogravimetry (TG) and differential scanning calorimetry (DSC) in nitrogen and oxygen environments. The calculated difference in the measured fG-residues run in different environments and obtained at temperatures close to 300 °C by a dynamic experiment indicate the action of oxygen on the formation of gaseous products. The rats constants and activation energies of the degradation process in both environments indicate the increase in stability due to the protection of hydroxyls by acetylation. In an inert environment xylans have one broad multicomponent exotherm, as determined by dynamic DSC measurement. In an oxygen environment two or three independent exotherms are observed. The pretreatment of xylan with trifluoroacetic acid (solvent used for acetylation) and acetylation lowers the exothermic effect of both the thermolysis and thermooxidation. The recycling of the acetylated xylan to Na + -salt form leads to a greater exothermic effect of the degradation in both environments.

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“…From Figure 3, it was seen that all the membranes showed three degradation steps. These three steps may correspond to the steps suggested by Scotney, 14,23 representing the thermal degradation of the CA. The first step starts at 102 C and ends at 316 C, representing the loss of the acetyl groups, followed by the acetic acid catalyzed decomposition of cellulose, and the removal of the residual solvent or moisture.…”

Section: Thermogravimetric Analysismentioning

confidence: 96%

Effect of poly(ether–ether–sulfone) concentration on the morphology, performance, thermal stability, mechanical strength, and antifouling of asymmetric cellulose acetate ultrafiltration membranes

Maheswari

Mohan

2013

High Performance Polymers

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The aim of the present work is to investigate the morphology, performance, thermal stability, mechanical strength, and antifouling of the poly(ether-ether-sulfone) (PEES)-incorporated asymmetric cellulose acetate (CA)-blended ultrafiltration membranes. High-performance CA/PEES blend ultrafiltration membranes were prepared by the phase inversion technique. The effects of PEES concentration (0-30 wt%) on pure water permeability (PWP), water content, porosity, molecular weight cutoff, mean pore size, morphology, hydrophilicity, and thermal and mechanical properties of the CA/PEES blend membranes were investigated. Morphological studies were carried out using scanning electron microscopy. scanning electron microscopic studies revealed that the incorporation of PEES resulted in the formation of a thin top layer, a porous sub-layer, and the open pores in the bottom layer. The thermal properties of these polymeric membranes were evaluated by thermogravimetric and differential thermogravimetric analyses measurements, whereas the glass transition temperature of the membranes was calculated by differential scanning calorimetry. With the increase in the concentration of PEES on the CA membranes, the PWP, hydrophilicity, water content, porosity, the thermal stability, glass transition temperature, tensile strength, tensile modulus, and elongation at break significantly improved in the blend membranes. The efficiency of these membranes in the separation of commercially important proteins such as bovine serum albumin (BSA), egg albumin, pepsin, and trypsin was studied and found to be enhanced as compared to CA membranes. In fouling experiments, BSA was used as the model protein, and flux recovery ratio (FRR) of the membranes was calculated. Attempts have been made to correlate the changes in membrane morphology with pure water flux, water content, porosity, thermal and mechanical stability, separation efficiency, and antifouling property of the CA/PEES membranes. It has been demonstrated that the fouling-resistant ability of CA/PEES membranes is enhanced due to the high FRR with the addition of PEES in the casting solution. Based on the findings, it can be concluded that the membranes prepared with 80/20 composition of CA/PEES blend membranes are promising candidates for industrial applications.

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The thermal degradation of cellulose triacetate—I. The reaction products

Cited by 29 publications

References 10 publications

Phosphorylated cellulose propionate derivatives as thermoplastic flame resistant/retardant materials: influence of regioselective phosphorylation on their thermal degradation behaviour

Phosphorylated cellulose propionate derivatives as thermoplastic flame resistant/retardant materials: influence of regioselective phosphorylation on their thermal degradation behaviour

Thermal Degradation and Thermooxidation of O-Acetyl-(4-O-methyl-D-glucurono)-D-xylan and Related Derivatives

Effect of poly(ether–ether–sulfone) concentration on the morphology, performance, thermal stability, mechanical strength, and antifouling of asymmetric cellulose acetate ultrafiltration membranes

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