An ultrasensitive technique for testing the Arrhenius extrapolation assumption for thermally aged elastomers

Wise, Jonathan; Gillen, K.T.; Clough, R.L.

doi:10.1016/0141-3910(95)00137-b

Cited by 199 publications

(96 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Most studies involving a kinetics analysis based on the TTSP are related to the mechanical and electrical relaxation behavior of various polymers. 19,20) Recently, the TTSP has been adopted in other fields, such as the natural aging of cellulose. Here, we employed a method previously reported by Ding and Wang 21,22) and Matsuo et al 23,24) The TTSP regards both time and temperature as equals; that is, the values of a color parameter obtained for a short time at an accelerated aging temperature are identical to those measured for a longer time at a moderate temperature.…”

Section: Experimental Materialsmentioning

confidence: 99%

Prediction of Color Changes Using the Time–Temperature Superposition Principle in Liquid Formulations

Mochizuki

Takayama

2014

CHEMICAL & PHARMACEUTICAL BULLETIN

View full text Add to dashboard Cite

This study reports the results of applying the time-temperature superposition principle (TTSP) to the prediction of color changes in liquid formulations. A sample solution consisting of L-tryptophan and glucose was used as the model liquid formulation for the Maillard reaction. After accelerated aging treatment at elevated temperatures, the Commission Internationale de l'Eclairage (CIE) LAB color parameters (a*, b*, L*, and E*ab) of the sample solution were measured using a spectrophotometer. The TTSP was then applied to a kinetic analysis of the color changes. The calculated values of the apparent activation energy of a*, b*, L*, and ΔE*ab were 105.2, 109.8, 91.6, and 103.7 kJ/mol, respectively. The predicted values of the color parameters at 40°C were calculated using Arrhenius plots for each of the color parameters. A comparison of the relationships between the experimental and predicted values of each color parameter revealed the coefficients of determination for a*, b*, L*, and ΔE*ab to be 0.961, 0.979, 0.960, and 0.979, respectively. All the R 2 values were sufficiently high, and these results suggested that the prediction was highly reliable. Kinetic analysis using the TTSP was successfully applied to calculating the apparent activation energy and to predicting the color changes at any temperature or duration.Key words color change; prediction; time-temperature superposition principle; Maillard reactionThe color of pharmaceutical products is an important quality attribute. Color changes in pharmaceutical products are often indicative of either poor-quality production or product instability.1,2) Color measurement is one type of quality assurance test that should be performed during the development of pharmaceutical products.3) Techniques for preventing changes in the color of the product are often used. For example, the use of antioxidant agents and color agents is a common solution for stabilizing the color appearance of products. 4) In some cases, however, color changes occur very slowly over time. If a commercialized product exhibits a color change before it can be sold, the product should be recalled. Therefore, a method for predicting color changes is important for the development of products within a short time period and for determining the shelf-life of a product. In the food industry, methods for predicting color changes over time have been thoroughly studied as an index of quality. Several reports have discussed the kinetics of color changes in food products, such as broccoli juice, 5) apple puree, 6) and green asparagus. 7) In the pharmaceutical industry, kinetic analyses of changes in the color of solid dosage forms have been reported with a variety of purpose, including the prediction of discoloration, 8) evaluations of the coloration of photosensitive solid drugs, 9) elucidation of the discoloration kinetics of uncoated white tablets, 10) examinations of coloration during long-term stability tests, 11) and the examination of color stabilization through the use of film coating.12) On the other...

show abstract

Section: Experimental Materialsmentioning

confidence: 99%

Prediction of Color Changes Using the Time–Temperature Superposition Principle in Liquid Formulations

Mochizuki

Takayama

2014

CHEMICAL & PHARMACEUTICAL BULLETIN

View full text Add to dashboard Cite

show abstract

“…The O-18 backfill pressure was chosen so that the partial pressure of oxygen in the vessel for the experiment at the elevated aging temperature was slightly greater than that of ambient air in our laboratory. This pressure ensured enough oxygen was present for degradation to occur under simulated ambient conditions [10,27].…”

Section: Accelerated Agingmentioning

confidence: 99%

“…Previous reports have studied nylon 6.6 degradation through chemiluminescence [6], UV/VIS spectroscopy [7][8][9][10], nuclear magnetic resonance (NMR) [11], Fourier transform infrared spectroscopy (FTIR) [12][13][14], mass spectrometry (MS) [15,16], and gas chromatography/mass spectrometry (GC/MS) [17]. Most recently, Gröning and Hakkarainen employed headspace solid-phase microextraction with gas chromatography/mass spectrometry (HS-SPME-GC/MS) to identify and characterize volatile thermal-oxidative degradation species and detailed degradation mechanisms of polyamide 6.6 [18][19][20].…”

mentioning

confidence: 99%

Characterization of Volatile Nylon 6.6 Thermal-Oxidative Degradation Products by Selective Isotopic Labeling and Cryo-GC/MS

Smith

White

et al. 2012

J. Am. Soc. Mass Spectrom.

View full text Add to dashboard Cite

Aged materials, such as polymers, can exhibit modifications to their chemical structure and physical properties, which may render the material ineffective for its intended purpose. Isotopic labeling was used to characterize low-molecular weight volatile thermal-oxidative degradation products of nylon 6.6 in an effort to better understand and predict changes in the aged polymer. Headspace gas from aged (up to 243 d at 138°C) nylon 6.6 monomers (adipic acid and 1,6-hexanediamine) and polymer were preconcentrated, separated, and detected using cryofocusing gas chromatography mass spectrometry (cryo-GC/MS). Observations regarding the relative concentrations observed in each chromatographic peak with respect to aging time were used in conjunction with mass spectra for samples aged under ambient air to determine the presence and identity of 18 degradation products. A comparison of the National Institute of Standards and Technology (NIST) library, unlabeled, and isotopically labeled mass spectra (C-13 or N-15) and expected fragmentation pathways of each degradation product were used to identify the location of isotopically labeled atoms within the product's chemical structure, which can later be used to determine the exact origin of the species. In addition, observations for unlabeled nylon 6.6 aged in an O-18 enriched atmosphere were used to determine if the source of oxygen in the applicable degradation products was from the gaseous environment or the polymer. Approximations for relative isotopic ratios of unlabeled to labeled products are reported, where appropriate.

show abstract

“…Therefore, the time-dependency of the properties at the surface are used to determine the activation energy, for example, the data in Fig.4(a) and Fig.4(c). The principle of time/temperature superposition by shifting the raw data to a selected reference temperature T ref is employed 19) . This principle is shown in Fig.14.…”

Section: (3) Activation Energymentioning

confidence: 99%

Long-Term Deterioration of High Damping Rubber Bridge Bearing

Itoh

Satoh

et al. 2006

JSCE JOURNAL OF STRUCTURAL AND EARTHQUAKE ENGINEERING

View full text Add to dashboard Cite

In recent years, high damping rubber (HDR) bridge bearings have become widely used because of the excellent ability to provide high damping as well as flexibility. However, there are few systematic studies on the deterioration problems of HDRs during their service life, and usually the long-term performance was not considered in the design stage. In this research, through accelerated thermal oxidation tests on HDR blocks, the property variations inside the HDR bridge bearing are examined. A deterioration prediction model is developed to estimate the property profiles. Then using a constitutive model and carrying out FEM analysis, the behavior of a HDR bridge bearing during its lifespan is clarified. A design procedure is proposed that takes the long-term performance in the site environment into consideration.

show abstract

An ultrasensitive technique for testing the Arrhenius extrapolation assumption for thermally aged elastomers

Cited by 199 publications

References 25 publications

Prediction of Color Changes Using the Time–Temperature Superposition Principle in Liquid Formulations

Prediction of Color Changes Using the Time–Temperature Superposition Principle in Liquid Formulations

Characterization of Volatile Nylon 6.6 Thermal-Oxidative Degradation Products by Selective Isotopic Labeling and Cryo-GC/MS

Long-Term Deterioration of High Damping Rubber Bridge Bearing

Contact Info

Product

Resources

About