Alternating copolymerization of carbon dioxide and epoxide catalyzed by the aluminum porphyrin-quaternary organic salt or -triphenylphosphine system. Synthesis of polycarbonate with well-controlled molecular weight

1986 ◽  
Vol 19 (1) ◽  
pp. 8-13 ◽  
Author(s):  
Takazo Aida ◽  
Masahide Ishikawa ◽  
Shohei Inoue
Keyword(s):  
Carbon Dioxide ◽  
Molecular Weight ◽  
Organic Salt ◽  
System Synthesis ◽  
Alternating Copolymerization

Chiral salenCo(iii) complexes with bulky substituents as catalysts for stereoselective alternating copolymerization of racemic propylene oxide with carbon dioxide and succinic anhydride

2021 ◽  
Vol 12 (12) ◽  
pp. 1776-1786
Author(s):  
Zhou Wang ◽  
Ying Mu
Keyword(s):  
Carbon Dioxide ◽  
Propylene Carbonate ◽  
Propylene Oxide ◽  
Succinic Anhydride ◽  
Poly Propylene ◽  
Alternating Copolymerization

Stereoregular poly(propylene carbonate)s and poly(propylene succinate-block-carbonate)s were synthesized with new chiral salenCo(iii) catalysts carrying bulky substituents.

RFID-Based Thermal Bubble Non-Floating Type Accelerometer with Semi-Cylindrical Chamber and Filled with Xenon Gas

2011 ◽  
Vol 317-319 ◽  
pp. 1153-1162
Author(s):  
Jium Ming Lin ◽  
Po Kuang Chang ◽  
Cheng Hung Lin ◽  
Qi Kun Zhang
Keyword(s):  
Carbon Dioxide ◽  
Molecular Weight ◽  
Response Time ◽  
Flexible Substrate ◽  
Thermal Sensors ◽  
Cylindrical Chamber ◽  
Floating Structure ◽  
Key Technology ◽  
Impact Condition ◽  
Floating Type

This research proposes a wireless RFID-based thermal bubble accelerometer design, and relates more particularly for the technology to manufacture and package it on a flexible substrate. The key technology is to integrate both a thermal bubble accelerometer and a wireless RFID antenna on the same substrate, such that the accelerometer is very convenient for fabrication and usage. In this paper the heaters as well as the thermal sensors are directly adhering on the surface of the flexible substrate without the traditional floating structure. Thus the structure is much simpler and cheaper for manufacturing, and much more reliable in large acceleration impact condition without broken. Furthermore, the molecular weight of xenon gas is much larger than carbon dioxide, thus the performance of the accelerometer will be increased. In addition, the shape of the chamber is changed as a semi-cylindrical one instead of the conventional rectangular type. Comparisons of sensitivity and response time are also made; one can see the performances of the proposed new design with either semi-cylindrical chamber or filled with xenon gas are better.

scholarly journals Tertiary Amines Paired with Trialkyl Boranes: A Simple Organocatalyst for Fully Alternating Copolymerization of Carbon Dioxide and Propylene Oxide

2020 ◽  
Author(s):  
Xing-Hong Zhang
Keyword(s):  
Carbon Dioxide ◽  
Small Molecules ◽  
Propylene Oxide ◽  
Average Molecular Weight ◽  
Tertiary Amines ◽  
Carbon Dioxide Co2 ◽  
Poly Propylene ◽  
Alternating Copolymerization ◽  
Completely Alternating ◽  
Huge Challenge

Metal-free synthesis of fully alternating polycarbonates from carbon dioxide (CO2) and epoxides is highly desired but a huge challenge. Here, we disclose the combination of tertiary amines with trialkyl boranes for completely alternating copolymerization of CO2 with epoxides. Triethylamine (TEA) pairing with triethyl borane (TEB), the simplest catalyst for the copolymerization of CO2 and propylene oxide (PO), afforded fully alternating poly(propylene carbonate) (PPC) with a turnover frequency (TOF) of 54 h-1 at 60 oC. Remarkably, diamine such as, N,N,N',N'-tetraethylethylenediamine (TEED) and triamine such as N,N,N',N'',N''-pentamethyldiethylene triamine (PMDETA) pairing with TEB exhibited improved the copolymer selectivity of up to 99%. Supplementally, the effect of trialkylborane structure on the copolymerization were also investigated. Moreover, PPCs prepared from these tertiary amines/ trialkyl boranes Lewis pairs showed the head-to-tail diad content of around 80%. The number-average molecular weight of PPC was up to 56.0 kg/mol with narrow distribution (Đ =1.16) and could be easily adjusted by simply varying the feeding ratios. The 1H NMR spectra and MALDI-TOF-MS spectra suggest that both tertiary amine-activating CO2 and TEB-masked end anions cooperatively promote the fully alternating CO2/epoxide copolymerization. This work provides an organocatalytic platform for well-defined CO2/epoxide copolymers using simple small molecules with high atomic utilization.<br>

Effect of stabilizer concentration and controller structure and composition on polymerization rate and molecular weight development in RAFT polymerization of styrene in supercritical carbon dioxide

Polymer ◽  
2009 ◽  
Vol 50 (21) ◽  
pp. 5024-5030 ◽  
Author(s):  
Gabriel Jaramillo-Soto ◽  
Pedro R. García-Morán ◽  
Francisco J. Enríquez-Medrano ◽  
Hortensia Maldonado-Textle ◽  
Martha E. Albores-Velasco ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Molecular Weight ◽  
Supercritical Carbon Dioxide ◽  
Raft Polymerization ◽  
Polymerization Rate ◽  
Stabilizer Concentration ◽  
Supercritical Carbon

Alternating Copolymerization of Carbon Dioxide with Cyclohexene Oxide Catalyzed by a Novel Catalyst

2012 ◽  
Vol 549 ◽  
pp. 445-448
Author(s):  
Li Dan Fan ◽  
Gang Qin ◽  
Xin Xin Cao ◽  
Shao Kui Cao
Keyword(s):  
Carbon Dioxide ◽  
Catalytic Activity ◽  
Reaction Time ◽  
Zinc Complex ◽  
Cyclohexene Oxide ◽  
Novel Catalyst ◽  
Alternating Copolymerization

A novel catalyst for the copolymerization of CO2 and cyclohexene oxide(CHO) was prepared by using BTE and ZnCl2. The zinc complex showed catalytic activity for the copolymerization. The obtained copolymer was characterized by IR and NMR. Effect of reaction time on copolymerization was investigated.

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