Kinetic Aspects of the Thermal Degradation of a Temporary Binder Modified with Vitreous Molasses for Use in Making High-Temperature Periclase Refractories

2014 ◽  
Vol 54 (6) ◽  
pp. 479-484
Author(s):  
S. I. Borovik ◽  
G. A. Lysova ◽  
A. M. Chuklai
Keyword(s):  
High Temperature ◽  
Thermal Degradation ◽  
Temporary Binder

Room-temperature Repeatedly Processable Baroplastic/Boron Nitride Thermal Management Composite

2021 ◽  
Author(s):  
Jia-Ning Qiao ◽  
Yu Fan Hu ◽  
Xu Ji ◽  
Jian-Hua Tang ◽  
Jun Lei ◽  
...  
Keyword(s):  
High Temperature ◽  
Boron Nitride ◽  
Thermal Degradation ◽  
Energy Saving ◽  
Thermal Management ◽  
Room Temperature ◽  
High Repeatability

Baroplastics show great superiorities over common polymers that are processed at high temperature, such as energy-saving, less thermal degradation, high repeatability and durability, etc. In this work, we synthesized a...

Thermal Degradation of Hydroxyl-Terminated Poly(L-Lactic Acid) Oligomer into L-Lactide

2010 ◽  
Vol 152-153 ◽  
pp. 222-228 ◽  
Author(s):  
Jun Shen ◽  
Rong Qing Wei ◽  
Ying Liu ◽  
Xiao Ning Liu ◽  
Yu Zhong
Keyword(s):  
Lactic Acid ◽  
High Temperature ◽  
Carboxylic Acid ◽  
Thermal Degradation ◽  
Adipic Acid ◽  
Degradation Mechanism ◽  
Practical Approach ◽  
Condensation Polymerization ◽  
Speed Up ◽  
Degradation Behaviors

This study investigates the thermal degradation of poly(L-lactic acid) (PLLA) oligomers into L-lactide（LA）by modification of the oligomer terminal groups. Pure PLLA oligomer (OLLA) was synthesized by condensation polymerization of L-lactic acid. Poly-hydroxyl-terminated OLLA (OLLAPOH) and two-carboxylic acid-terminated OLLA (OLLACOOH) were prepared by adding a small amount of polyfunctional substance, such as 1,4-butanediol, pentaerythritol, or adipic acid, to L-lactic acid. The thermal degradation behaviors of these oligomers were compared at 210-220 °C under 0.3-0.5 kPa. The results show that OLLAPOH has a 10-20% higher yield than OLLA and OLLACOOH. The order of decreasing yield is as follows: OLLAPOH>OLLA >OLLACOOH. The hydroxyl ends of the chains induce the reaction. OLLAPOH simultaneously starts depolymerization from each hydroxyl end to speed up the reaction, to shorten the time the substance remains at high temperature, and to reduce the byproducts. This results in an increased L-lactide yield. A practical approach for L-lactide production by thermal degradation of OLLAPOH is adopted by using a degradation mechanism, which is an unzipping reaction beginning from the hydroxyl ends of the chains.

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