Morphology and properties of high molecular weight polyisobutylene and thermoplastic polyurethane elastomer

2021 ◽  
pp. 51466
Author(s):  
Jixiang Jia ◽  
Peng Lin ◽  
Qiang Liu
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Thermoplastic Polyurethane ◽  
Polyurethane Elastomer ◽  
Thermoplastic Polyurethane Elastomer ◽  
High Molecular Weight Polyisobutylene

Thermoplastic Polyurethane Elastomer Melt Polymerization Study

1982 ◽  
Vol 55 (1) ◽  
pp. 137-150 ◽  
Author(s):  
C. S. Schollenberger ◽  
K. Dinbergs ◽  
F. D. Stewart
Keyword(s):  
Molecular Weight ◽  
Thermoplastic Polyurethane ◽  
Degree Of Polymerization ◽  
Virtual Network ◽  
Polymer Composition ◽  
Polymerization Temperature ◽  
Quiescent State ◽  
Polyurethane Elastomer ◽  
Melt Polymerization ◽  
Thermoplastic Polyurethane Elastomer

Abstract It is concluded from the present study that the slightly modified Brabender PlastiCorder torque rheometer is well suited to the study of thermoplastic polyurethane elastomer melt polymerization. The instrument is sensitive and responsive enough over a broad range to sense and record continuously even small changes in polymerizate temperature and viscosity as a function of time. This capability has enabled us to follow the full course of such polymerizations, with the exception of the final polymer maturation process which customarily is effected in the quiescent state. In our study, the effects of several polymerization variables were clearly and quantitatively apparent, including the effects on the course of polymerization and its degree of: macroglycol acidity; antioxidant (stabilizer); temperature; catalyst; polymer composition; presence of shortstop; and reactant balance. The results demonstrate the known acid catalysis of the hydroxyl-isocyanate reaction as well as polyurethane molecular weight modification by polyester glycol acidity. The inclusion of a commercial phenolic antioxidant in the polymerization charge did not have any obvious effect on the course of polymerization but may have limited degree of polymerization somewhat. Increased urethane content greatly speeds the viscosity increase, demonstrating urethane autocatalysis as well as its viscosity contribution, and even low stannous octoate catalyst levels appreciably speeded the inherently rapid polymerization. The shortstopping action of fugitive and persistent primary alcohols is prompt and effective, but excessive amounts produce some irreversible polymer reversion as they readjust the polymer chain molecular weight distribution present in maintaining the urethane equilibrium. This equilbrium also showed clear response to polymerization temperature, reversible urethane dissociation reducing viscosity with increasing temperature. The effect of polymerization reactant imbalance was readily apparent in the appreciably reduced rate and degree of polymerization attending minor isocyanate deficiency. Mastication experiments in the PlastiCorder show dried preformed polyurethane elastomer to drop quickly to viscosity levels much below that reached by the same compositions during polymer formation. The viscosity loss of the former is attributed to polyurethane chain rupture promoted by virtual network restrictions to chain slippage, while the virtual network has not yet developed in the forming polymer.

Fire safety improvement of para-aramid fiber in thermoplastic polyurethane elastomer

2017 ◽  
Vol 324 ◽  
pp. 789-796 ◽  
Author(s):  
Xilei Chen ◽  
Wenduo Wang ◽  
Shaoxiang Li ◽  
Chuanmei Jiao
Keyword(s):  
Fire Safety ◽  
Thermoplastic Polyurethane ◽  
Aramid Fiber ◽  
Polyurethane Elastomer ◽  
Safety Improvement ◽  
Thermoplastic Polyurethane Elastomer

scholarly journals Novel phenolic resin hollow microspheres: Flame retardancy and toxicity reduction in thermoplastic polyurethane elastomer

2021 ◽  
Vol 15 (9) ◽  
pp. 887-898
Author(s):  
C. M. Jiao ◽  
Y. L. Zhang ◽  
H. X. Dong ◽  
W. J. Chen ◽  
W. Liu ◽  
...  
Keyword(s):  
Flame Retardancy ◽  
Phenolic Resin ◽  
Thermoplastic Polyurethane ◽  
Hollow Microspheres ◽  
Polyurethane Elastomer ◽  
Toxicity Reduction ◽  
Thermoplastic Polyurethane Elastomer
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