Review on the thermo-oxidative degradation of polymers during processing and in service

Gijsman, Pieter

doi:10.1515/epoly.2008.8.1.727

Cited by 72 publications

(52 citation statements)

References 138 publications

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“…Most of the polymers are applied below their processing temperature and hardly degrade in an environment without oxygen. The reduction of properties in natural environment is a result of reactions with oxygen 77. The thermal oxidative degradation of polymers can provide practical and important information on how polymeric materials behave under more realistic atmospheric conditions 78, 79.…”

Section: Thermal Decomposition In Open Systemmentioning

confidence: 99%

Thermal degradation and stability of starch under different processing conditions

Liu¹,

Wang²,

et al. 2012

Starch Stärke

265

145

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The objectives of this paper are to review the thermal degradation and stability of starch and starch‐based materials, including both fundamental sciences such as detecting techniques, the effect of amylose/amylopectin content in starches and starches modifications, as well as the effect of different processing environments, such as an open or sealed system, and shearless or shear stress conditions. The decomposition temperature of starches was increased with increasing amylopectin content in an open system. In the open system, the initial water content did not affect the decomposition temperature because all water had evaporated from samples prior to reaching the decomposition temperature. Two decomposition temperatures were observed in the sealed system: the first at lower temperature represents long chain scission; and the second at higher temperature involves decomposition of glucose ring. In the sealed system, the first degradation was increased with increasing amylopectin content. There is no observable difference of the second degradation for the samples containing different amylose/amylopectin ratios. The higher the moisture content is, the lower the second decomposition temperature is detected in the sealed system. Significant shear degradation was observed in amylopectin component of starch, while high amylose starch proved less sensitive to shear stress. The achievements in this area have increased the knowledge of polymer science, in particular to understand the degradation of natural polymers.

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Section: Thermal Decomposition In Open Systemmentioning

confidence: 99%

Thermal degradation and stability of starch under different processing conditions

Liu¹,

Wang²,

et al. 2012

Starch Stärke

265

145

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“…Polyethylene is one of the important commodity polymers in the market, and it is therefore not surprising that many efforts were focused on understanding the thermooxidative degradation of polyethylene, since degradation is of crucial relevance for processing [Hinsken et al (1991); Johnston and Morrison (1996); Epacher et al (2000)], for performance under service conditions [Gijsman (2008)], and for recycling [Hakkarainen and Albertsson (2004); Roy et al (2011)]. Chain scission and cross-linking [Arnett and Stacy (1966); Meltzer and Supnik (1964)] as well as long-chain branching (LCB) [Holmstr€ om and S€ orvik (1974)] have been identified as the main structural modifications in polyethylene as a consequence of thermal degradation.…”

Section: Introductionmentioning

confidence: 99%

Increase of long-chain branching by thermo-oxidative treatment of LDPE: Chromatographic, spectroscopic, and rheological evidence

Rolón-Garrido¹,

Zatloukal²,

Wagner³

2013

Journal of Rheology

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SynopsisLow-density polyethylene was thermo-oxidatively degraded at 170 C, i.e., degraded in the presence of air, by a one thermal cycle (1C) treatment during times between 30 and 90 min, and by a two thermal cycles (2C) treatment, i.e., after storage at room temperature, an already previously degraded sample was further degraded during times between 15 and 45 min. Characterization methods include gel permeation chromatography (GPC), Fourier transform infrared (FTIR) spectroscopy, as well as linear and nonlinear rheology. A reduction of molar mass was detected for all degraded samples by GPC, as well as an increase of the high molar mass fraction of the 1C sample degraded for the longest time. Intrinsic viscosity measurements indicate also a reduction of molar mass with increasing degradation times for both 1C and 2C samples. Thermo-oxidation is confirmed for 1C and 2C samples by analyzing specific indices in FTIR. Linear viscoelasticity seems to be in general only marginally affected by thermo-oxidative exposure, while the enhanced strain-hardening effect observed in uniaxial extension experiments presents a clear evidence for an increased long-chain branching (LCB) content in both 1C and 2C samples. Elongational viscosity data were analyzed by the molecular stress function (MSF) model as well as the Wagner-I model, and for both models, quantitative description of the experimental data for all samples was achieved by fit of only one nonlinear model parameter. Time-deformation separability was confirmed for all samples degraded, 1C as well as 2C, for cumulative degradation times of up to 90 min. The characterization by GPC was confronted with the characterization obtained from nonlinear rheology. It can be stated that elongational rheology is a powerful method to detect structural a) Author to whom correspondence should be addressed; electronic mail: victor.h.rolongarrido@tu-berlin.de

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“…This large discrepancy is the consequence of the difference in dose effects, which disfavors the elastomer. Several results reported the susceptibility of ethylene-propylene diene copolymer to oxidation under ionizing radiation exposure in the absence of stabilizer [30,31]. The EPDM phase can be considered as the part of material where oxidation starts earlier.…”

Section: Resultsmentioning

confidence: 99%

Study on radiation aging of PA6/EPDM blends

Zaharescu¹,

Lungulescu²,

Caramitu³

et al. 2015

Iran Polym J

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Review on the thermo-oxidative degradation of polymers during processing and in service

Cited by 72 publications

References 138 publications

Thermal degradation and stability of starch under different processing conditions

Thermal degradation and stability of starch under different processing conditions

Increase of long-chain branching by thermo-oxidative treatment of LDPE: Chromatographic, spectroscopic, and rheological evidence

Study on radiation aging of PA6/EPDM blends

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