Structure vs stability in polymer degradation

Stivala, Salvatore; Reich, Leo

doi:10.1002/pen.760201003

Cited by 38 publications

(17 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Weakening of such interactions is known to lower the thermal stability of polymers. [40,41] To measure the glass transition temperature of the resulting polymer we have tried to employ conventional DSC. However, this technique has failed to detect the transition in a range of 25-400 °C.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and Polymerization Kinetics of Novel Dicyanate Ester Based on Dimer of 4‐tert‐butylphenol

Galukhin

Nosov

Taimova

et al. 2021

Macro Chemistry & Physics

View full text Add to dashboard Cite

A novel dicyanate ester, which constitutes the first member of the family of linear oligomers of 4‐tert‐butyl‐phenol, is synthesized as a part of the systematic study on the relation between the reactivity of cyanate esters and their structure. The synthesized monomer undergoes thermally stimulated polymerization in the melt. The kinetics of polymerization is studied by conventional and temperature‐modulated DSC. Detailed isoconversional analysis of the obtained kinetic data has revealed that the process rate is limited by a single reaction step of the auto‐catalytic nature. Thermal stability and glass transition temperature of polymerization product are characterized by means of thermogravimetry and fast scanning calorimetry.

show abstract

Section: Resultsmentioning

confidence: 99%

Synthesis and Polymerization Kinetics of Novel Dicyanate Ester Based on Dimer of 4‐tert‐butylphenol

Galukhin

Nosov

Taimova

et al. 2021

Macro Chemistry & Physics

View full text Add to dashboard Cite

show abstract

“…Oxidation of polyethylene incubated at temperatures below its melting temperature, is limited to the amorphous phase since crystallites are impermeable to oxygen (Hawkins et al 1959;Holmström 1979;Stivala and Reich 1980). Hence, a small degree of oxidation in the amorphous regions can dramatically change the polymer properties (Scheirs 2000).…”

Section: Changes In the Polymer Morphology Due To Chemical Degradatiomentioning

confidence: 99%

Effect of high temperatures on the physical and mechanical properties of HDPE geomembranes in air

Abdelaal

Rowe

Hsuan

et al. 2015

Geosynthetics International

View full text Add to dashboard Cite

The effect of elevated temperatures, particularly between 95 and 115°C as encountered in some geoenvironmental applications, on the physical and mechanical properties of high-density polyethylene (HDPE) geomembranes (GMBs) is examined. Four commercially available HDPE GMBs were incubated in air at temperatures ≥ 85°C. Investigation of the thermograms by differential scanning calorimetry showed a significant change in the polymer morphology with an increase of the incubation temperature and duration, especially at 105 and 115°C. The morphological changes due to annealing involve thickening of the lamella crystals of the polymer and a change in the tie molecules joining the lamella crystals. The effect of annealing was most evident in the stress crack resistance of the GMB incubated at 105 and 115°C prior to polymer degradation. In particular, an increase in stress crack resistance due to annealing could mask the effects of polymer degradation at temperatures above 95°C. Changes in morphology did not affect melt index whose changes were largely attributed to polymer degradation.

show abstract

“…The degradation process is initiated at the terminal units with subsequent depolymerization. For example paraformaldehyde with hydroxyl terminal starts to degrade at about 170°C whereas the same polymer with acetyl terminals decomposes at about 200°C [1]. Replacement of carbon main chain with hetero atoms like P, N, B increases the thermal stability e.g.…”

Section: Introductionmentioning

confidence: 99%