High-resolution thermogravimetry of cellulose esters

Li, Xin‐Gui

doi:10.1002/(sici)1097-4628(19990124)71:4<573::aid-app8>3.0.co;2-r

Cited by 24 publications

(10 citation statements)

References 7 publications

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“…The first step, between 400 and 500 C, is due to degradation of PET chains into smaller fragments by an initial scission of the chain end [47]. The second weight loss step, between 500 and 600 C, is related to thermo-oxidative degradation of the small fragments into volatile products [48,49]. All treated fabrics showed the same weight loss behavior, so only one curve is reported and considered representative.…”

Section: Thermal Stability Of Pet Fabricmentioning

confidence: 99%

Layer-by-layer assembly of silica-based flame retardant thin film on PET fabric

Carosio

Laufer

Alongi

et al. 2011

Polymer Degradation and Stability

223

105

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Section: Thermal Stability Of Pet Fabricmentioning

confidence: 99%

Layer-by-layer assembly of silica-based flame retardant thin film on PET fabric

Carosio

Laufer

Alongi

et al. 2011

Polymer Degradation and Stability

223

105

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“…The first weight loss step of waste PET occurred between about 340 and 450°C was due to the degradation of PET chains into smaller fragments by an initial scissoring of the chain end 15. The second weight loss step also occurred between about 450 and 550°C due to the thermo‐oxidative degradation of the small fragments into volatile products 16, 17. As clearly shown in Figure 3, incorporation of PLA to the polymer backbone decreases the degradation temperature of PET significantly.…”

Section: Resultsmentioning

confidence: 92%

“…PET shows interesting thermal characteristics and there are various studies about thermal degradation of PET, PET blends, and copolymers 3–17. On the other hand, the thermal degradations of polyesters18–22 and the degradation of polyolefins have been studied extensively under a variety of conditions 23–25…”

Section: Introductionmentioning

confidence: 99%

Thermal oxidative degradation kinetics and thermal properties of poly(ethylene terephthalate) modified with poly(lactic acid)

Acar

Pozan

Özgümüş

2008

J of Applied Polymer Sci

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ABSTRACT:The thermal oxidative degradation kinetics of poly(ethylene terephthalate) (PET) copolymers modified with poly(lactic acid) (PLA) were investigated with thermogravimetric analyzer (TGA). The thermal properties of the modified products were also determined by differential scanning calorimeter (DSC) technique. Waste PET (P100) obtained from postconsumer water bottles was modified with a low-molecular-weight PLA. The PET/PLA weight ratio was 90/10 (P90) and 50/50 (P50) in the modified samples. The thermal oxidative degradation kinetics of the modified samples was compared with those of PET (P100). The segmented block and/or random copolymer structure of the modified samples formed by a transesterification reaction between the PLA and PET units in solution and the length of the aliphatic and aromatic blocks were found to have a great effect on the degradation behavior. On the basis of the results of the degradation kinetics determined by Kissinger method, the degradation rate of the samples decreased in the order of P50 > P90 > P100, depending on the amount of PLA in the copolymer structure. However, the degradation activation energies (E A ) of the samples decreased in the order of P100 > P90 > P50. It was concluded that the degradation rate and mechanism were affected significantly by the incorporation of PLA into the copolymer structure.

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“…E a was calculated by the following equation derived from the Flynn, Wall, and Ozawa equations [14,15]: (4) where T r is the weight loss temperature and Ф is the heating rate (°C/min). C is a constant (0.4521).…”

Section: Samplementioning

confidence: 99%

Effects of an inorganic ammonium salt treatment on the flame-retardant performance of lyocell fibers

Kim¹,

Bai²,

In³

et al. 2016

Carbon letters

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Lyocell fibers are produced by dissolving cellulose in a N-methylmorpholine-N-oxide/ water solution. The resulting cellulose/N-methylmorpholine-N-oxide/water mixture is extruded through an orifice, drawn into an air gap, and then precipitated in a coagulation bath [1]. In contrast with rayon fibers, lyocell fibers have higher tenacity, a higher modulus, lower shrinkage when dried, and lower reductions of tenacity and the modulus when wet. Moreover, lyocell fibers are round and have molecular chains that are highly oriented along the fiber axis, and it is easy to control their fineness [2].However, lyocell fibers are often subjected to high temperatures, which can cause degradation of the fibers. When lyocell fibers are heated, they undergo a series of interrelated physical and chemical changes, including physical changes in weight, strength, color, and crystallinity. In addition, heat treatment can cause the material to move through different transitional phases and expand or contract, melt and recrystallize or undergo major structural changes [3].Thermal decomposition of the lyocell fibers leads to many kind of formations, such as solid residue, high-boiling point volatiles, and gaseous products. These kinds of products are formed through two competitive pathways. The first pathway involves many transformations, such as dehydration, rearrangement, carbonyl groups formation, the evolution of carbon monoxide and carbon dioxide, and the carbonaceous residue formation [4]. These phenomena take place rapidly in the presence of a variety of organic and inorganic catalysts, particularly Lewis acids, which catalyze the dehydration reactions. The second pathway competes with the first pathway and produces many oxygenated compounds and involves the thermal scission of glycosidic bonds between the glucopyranose units of cellulose [5]. These oxygenated compounds account for the majority of the weight loss of the solid residue. Therefore, it is important to control the reaction pathways during the initial pyrolysis stage to generate flame-retardant materials. Thus, flame-retardant enhanced lyocell fibers should be investigated for industrial applications. Recently, various treatment processes have been used to improve the flame-retardant properties of lyocell fibers. Because catalysts accelerate pyrolysis reactions, it is important to study the effects of catalysts on the pyrolysis of lyocell fibers. An effective catalyst should [6,7] decrease the pyrolysis temperature, increase the amounts of water and carbon dioxide produced during the reaction, and increase the amount of char formed.Therefore, it is important to control the reaction pathways during the initial stage of pyrolysis when generating flame-retardant materials. In this study, the effects of two different inorganic ammonium salts, (NH 4 ) 2 SO 4 and NH 4 Cl, on the flame-retardant properties of lyocell fibers were studied. Combining these salts could have a synergistic effect on the pyrolysis of lyocell fibers, including the induction of a slow pathway that invo...

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High-resolution thermogravimetry of cellulose esters

Cited by 24 publications

References 7 publications

Layer-by-layer assembly of silica-based flame retardant thin film on PET fabric

Layer-by-layer assembly of silica-based flame retardant thin film on PET fabric

Thermal oxidative degradation kinetics and thermal properties of poly(ethylene terephthalate) modified with poly(lactic acid)

Effects of an inorganic ammonium salt treatment on the flame-retardant performance of lyocell fibers

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