scholarly journals Color changes in wood during heating: kinetic analysis by applying a time-temperature superposition method

2010 ◽  
Vol 99 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Miyuki Matsuo ◽  
Misao Yokoyama ◽  
Kenji Umemura ◽  
Joseph Gril ◽  
Ken’ichiro Yano ◽  
...  
Keyword(s):  
Kinetic Analysis ◽  
Superposition Method ◽  
Color Changes ◽  
Temperature Superposition ◽  
Time Temperature Superposition

scholarly journals Aging of wood: Analysis of color changes during natural aging and heat treatment

Holzforschung ◽  
2011 ◽  
Vol 65 (3) ◽  
Author(s):  
Miyuki Matsuo ◽  
Misao Yokoyama ◽  
Kenji Umemura ◽  
Junji Sugiyama ◽  
Shuichi Kawai ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Oxidation Process ◽  
Color Change ◽  
Natural Aging ◽  
Superposition Method ◽  
Wood Color ◽  
Color Changes ◽  
Heat Treated ◽  
Temperature Superposition ◽  
Wood Analysis

Abstract The color properties of aging wood samples from historical buildings have been compared with those of recent wood samples that were heat treated at temperatures ranging from 90°C to 180°C. The results of kinetic analysis obtained by the time-temperature superposition method showed that the color change during natural aging was mainly due to a slow and mild oxidation process. In other words, heat treatment could accelerate the changes in wood color that occur during aging. In one sample, the color change (ΔE* ab ) after 921 years at ambient temperature was almost equivalent to that of heating (artificial aging) approximately for 6.7 h at 180°C. The results have been interpreted that the aging and the subsequent change in wood color begin at the time of tree harvesting.

scholarly journals Rate dependence of poly(vinyl chloride), the effects of plasticizer and time–temperature superposition

2014 ◽  
Vol 470 (2167) ◽  
pp. 20140012 ◽  
Author(s):  
Michael J. Kendall ◽  
Clive R. Siviour
Keyword(s):  
Vinyl Chloride ◽  
Analytical Investigation ◽  
Rate Dependence ◽  
Superposition Method ◽  
Compression Tests ◽  
Plasticizer Content ◽  
Poly Vinyl Chloride ◽  
Temperature Superposition ◽  
Thermal Analyser ◽  
Time Temperature Superposition

Four different poly(vinyl chloride) (PVC) materials varying in plasticizer content were studied in a combined experimental and analytical investigation including uniaxial compression tests at strain rates ranging from 10 −3 to 10 4  s −1 at room temperature, and temperatures ranging from −115 to 100°C at a rate of 10 −2  s −1 . Additional tests using a dynamic mechanical and thermal analyser were conducted on each PVC material to give a more detailed analysis of temperature and rate dependence. Adjusting the plasticizer content allows the temperature at which transitions, specifically the α-transition, or ‘glass transition’, and β-transition, occur to be moved in order to better examine the interplay of temperature and strain rate dependence. This program of research is then extended to time–temperature superposition where a novel application and interpretation of an established superposition method is presented.

scholarly journals Thermal modification kinetics and chemistry of poplar wood in dry and saturated steam media

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Bertrand Marcon ◽  
Gianluca Tondi ◽  
Lorenzo Procino ◽  
Giacomo Goli
Keyword(s):  
Research Work ◽  
Dry Mass ◽  
Treatment Temperature ◽  
Saturated Steam ◽  
Time Shift ◽  
Superposition Method ◽  
Wood Modification ◽  
Conversion Rates ◽  
Temperature Superposition ◽  
Time Temperature Superposition

Abstract This research work presents a modelling strategy to analyse thermal conversion rates of two thermal wood modification processes based on time-temperature superposition method. It gathers in a single study different original and bibliographic experimental works analysing the dry mass variation that occurs during thermal and hydro-thermal wood modification processes. The mass loss kinetic was successfully modelled using a modified Arrhenius approach. The time-temperature superposition method allowed to define for each wood modification process a master curve and its time shift depending on the treatment temperature. The analysis of ventilated oven and saturated steam treatments pointed out the existence of a continuous single kinetic for the ventilated oven which became more complex for saturated steam since a second kinetic stage appeared. This kinetic difference was sustained by infrared spectra chemical analysis which showed that hemicelluloses degraded much faster in presence of steam while lignin degradation occurred in both conditions.

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