Some new operational modes and parameters of stress relaxation for the viscoelastic characterization of solid polymers. I. The ?virtual modulus? mode

2002 ◽  
Vol 87 (2) ◽  
pp. 121-137 ◽  
Author(s):  
V. N. Kytopoulos ◽  
G. D. Bourkas ◽  
E. Sideridis
Keyword(s):  
Stress Relaxation ◽  
Solid Polymers ◽  
Operational Modes

Stress relaxation and optical characterization of TiO2 and SiO2 films grown by dual ion beam deposition

2008 ◽  
Vol 516 (23) ◽  
pp. 8604-8608 ◽  
Author(s):  
C. Bundesmann ◽  
I.-M. Eichentopf ◽  
S. Mändl ◽  
H. Neumann
Keyword(s):  
Stress Relaxation ◽  
Ion Beam ◽  
Optical Characterization ◽  
Sio2 Films ◽  
Ion Beam Deposition ◽  
Beam Deposition

scholarly journals Mechanical Characterization of Spray-Dried Granules by Compression and Stress-Relaxation Technique. Analysis of Relaxation Behavior.

1999 ◽  
Vol 107 (1252) ◽  
pp. 1183-1187 ◽  
Author(s):  
JunIchiro TSUBAKI ◽  
Takamasa MORI ◽  
Toshiyuki KONISHI ◽  
Akihisa TSURUTA ◽  
Hidetoshi MORI ◽  
...  
Keyword(s):  
Stress Relaxation ◽  
Mechanical Characterization ◽  
Relaxation Behavior ◽  
Relaxation Technique ◽  
Spray Dried ◽  
Technique Analysis

scholarly journals Recyclable Organocatalyzed Poly(Thiourethane) Covalent Adaptable Networks

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2913
Author(s):  
Francesco Gamardella ◽  
Sara Muñoz ◽  
Silvia De la Flor ◽  
Xavier Ramis ◽  
Angels Serra
Keyword(s):  
Stress Relaxation ◽  
Mechanical Characterization ◽  
Tensile Tests ◽  
Thermomechanical Analysis ◽  
Hexamethylene Diisocyanate ◽  
Relaxation Rates ◽  
Ftir Studies ◽  
New Type ◽  
And Performance

A new type of tetraphenylborate salts derived from highly basic and nucleophilic amines, namely 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), 1,8-diazabicyclo(5.4.0)undec-7-ene (DBU) and triazabicyclodecene (TBD), was applied to the preparation of networked poly(thiourethane)s (PTUs), which showed a vitrimer-like behavior, with higher stress-relaxation rates than PTUs prepared by using dibutyl thin dilaurate (DBTDL) as the catalyst. The use of these salts, which release the amines when heated, instead of the pure amines, allows the formulation to be easily manipulated to prepare any type of samples. The materials prepared from stoichiometric mixtures of hexamethylene diisocyanate (HDI), trithiol (S3) and with a 10% of molar excess of isocyanate or thiol were characterized by FTIR, thermomechanical analysis, thermogravimetry, stress-relaxation tests and tensile tests, thus obtaining a complete thermal and mechanical characterization of the materials. The recycled materials obtained by grinding the original PTUs and hot-pressing the small pieces in the optimized time and temperature conditions were fully characterized by mechanical, thermomechanical and FTIR studies. This allowed us to confirm their recyclability, without appreciable changes in the network structure and performance. From several observations, the dissociative interchange trans-thiocarbamoylation mechanism was evidenced as the main responsible of the topological rearrangements at high temperature, resulting in a vitrimeric-like behavior.

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